SECURITIES AND EXCHANGE COMMISSION

                             WASHINGTON, D.C. 20549

                                   FORM 8-K/A


                 Current Report Pursuant to Section 13 or 15(d)
                     of The Securities Exchange Act of 1934

       Date of Report (Date of earliest event reported) November 20, 2001


                             PS BUSINESS PARKS, INC.
                             -----------------------
             (Exact name of registrant as specified in its charter)


        CALIFORNIA                     1-10709                   95-4300881
        ----------                     -------                   ----------
(State or Other Jurisdiction   (Commission File Number)      (I.R.S. Employer
     of Incorporation)                                    Identification Number)


               701 Western AVenue, Glendale, California 91201-2397
               ---------------------------------------------------
               (Address of principal executive offices) (Zip Code)


       Registrant's telephone number, including area code: (818) 244-8080
                                                           --------------


                                       N/A
                                       ---
          (Former name or former address, if changed since last report)





ITEM 5.  OTHER EVENTS

PS Business Parks,  Inc.,  through its  consolidated  partnership  (collectively
referred to as the  "Company"),  acquired 12 buildings  known as the "Prosperity
Business Campus" and 12 buildings (including 24 acres of developable land) known
as the "Cornell  Oaks  Corporate  Center" on June 1, 2001 and November 20, 2001,
respectively,  at an aggregate  purchase price of approximately  $175.9 million.
The  Company is not  affiliated  with the  sellers  and the  purchase  price was
established through arm's length negotiations. The acquisitions were funded with
the  Company's  existing  cash  balances and  borrowings of $60 million from its
unsecured line of credit with Wells Fargo Bank.

The following  table  provides  certain  information  concerning  the facilities
acquired:





         Name and                                      Date of                       Purchase     Net Rentable    Occupancy
         Location                    Seller          Acquisition  Property Type        Price     Square Footage  at Closing
--------------------------- ----------------------  ------------- --------------  ------------- --------------- -------------
                                                                                              
Prosperity Business Campus   Olympia Properties,
  Fairfax, Virginia          L.L.C.                    6/1/01      Industrial &    $ 88,400,000       657,850        99%
                                                                      Office

Cornell Oaks Corporate       Talcott Realty I
  Center                     Limited Partnership     11/20/01     Industrial &       87,500,000      684,554         95%
  Beaverton, Oregon                                                  Office
                                                                                  ------------- --------------- -------------
                                                                                   $175,900,000     1,342,404        97%
                                                                                  ============= =============== =============


                                       1



Item 7. Financial Statements and Exhibits

(a)(3)   Financial Statements Specified by Rule 3.14 of Regulation S-X
         -------------------------------------------------------------

         Prosperity Business Campus

         o    Report of Independent Auditors

         o    Combined  Statements  of Certain  Revenues  and Certain  Operating
              Expenses for the nine months ended September 30, 2001  (unaudited)
              and for the year ended December 31, 2000

         o    Notes  to  Combined  Statements  of  Certain  Revenues and Certain
              Operating Expenses

         Cornell Oaks Corporate Center

         o    Report of Independent Auditors

         o    Combined  Statements  of Certain  Revenues  and Certain  Operating
              Expenses for the nine months ended September 30, 2001  (unaudited)
              and for the year ended December 31, 2000

         o    Notes  to  Combined  Statements  of  Certain  Revenues and Certain
              Operating Expenses

(b)      Pro Forma Consolidated Financial Statements
         -------------------------------------------

(c)      Exhibits
         --------
         23.  Consent of Independent Auditors


                                       2


                                   SIGNATURES


Pursuant  to the  requirements  of the  Securities  Exchange  Act of  1934,  the
Registrant  has duly  caused  this  report  to be  signed  on its  behalf by the
undersigned hereunto duly authorized.


                                                         PS BUSINESS PARKS, INC.


Date:  December 17, 2001                                   By: /S/ JACK CORRIGAN
                                                               -----------------
                                                                   Jack Corrigan
                                      Vice President and Chief Financial Officer


                                        3


                         REPORT OF INDEPENDENT AUDITORS



To the Board of Directors
of PS Business Parks, Inc.


We have audited the  accompanying  combined  statement  of certain  revenues and
certain operating expenses of the Prosperity Business Campus (as defined in Note
1)  ("Statement")  for the year ended  December 31, 2000.  The  Statement is the
responsibility of the Prosperity Business Campus' management. Our responsibility
is to express an opinion on the above mentioned Statement based on our audit.

We conducted our audit in accordance with auditing standards  generally accepted
in the United States. Those standards require that we plan and perform the audit
to obtain  reasonable  assurance about whether the Statement is free of material
misstatement.  An audit includes examining, on a test basis, evidence supporting
the amounts and disclosures in the Statement.  An audit also includes  assessing
the accounting principles used and significant estimates made by management,  as
well as evaluating the overall Statement presentation. We believe that our audit
provides a reasonable basis for our opinion.

The  accompanying  Statement was prepared for the purpose of complying  with the
rules and regulations of the Securities and Exchange Commission.

In our opinion,  the Statement presents fairly the combined certain revenues and
certain operating expenses of the Prosperity  Business Campus for the year ended
December 31, 2000, in conformity with accounting  principles  generally accepted
in the United States.





                                                               ERNST & YOUNG LLP





Los Angeles, California
July 14, 2001

                                       4



                         THE PROSPERITY BUSINESS CAMPUS
     Combined Statements of Certain Revenues and Certain Operating Expenses


                                          Nine months ended        Year ended
                                          September 30, 2001   December 31, 2000
                                        --------------------- ------------------
                                             (Unaudited)

Certain rental revenues...............    $    9,731,000        $  11,572,000
Certain operating expenses............        (2,625,000)          (3,254,000)
                                        --------------------- ------------------
Certain  rental  revenues  in  excess
     certain operating expenses.......    $    7,106,000        $   8,318,000
                                        ===================== ==================


                             See accompanying notes
                                       5


                         THE PROSPERITY BUSINESS CAMPUS
 Notes to Combined Statements of Certain Revenues and Certain Operating Expenses


1.       Background and Basis for Presentation

         The  accompanying  combined  statements of certain revenues and certain
         operating  expenses  include the  accounts of the  Prosperity  Business
         Campus  located in Virginia  and acquired by PS Business  Parks,  Inc.,
         through its consolidated  partnership  (collectively referred to as the
         "Company")  on June 1, 2001.  The  statements  are prepared in order to
         comply with Rule 3.14 of Regulation  S-X of the Securities and Exchange
         Commission.

         The  combined  statements  of certain  revenues  and certain  operating
         expenses  include only the accounts and  activities  of the  Prosperity
         Business Campus. Items that are not comparable to the future operations
         of the  Prosperity  Business  Campus  have been  excluded.  Such  items
         include depreciation,  amortization,  management fees, interest income,
         professional  fees,   miscellaneous   income  and  straight  line  rent
         adjustments.

         An audited statement is being presented for the most recent fiscal year
         available instead of the three most recent years based on the following
         factors:  (i) the Prosperity Business Campus was acquired from a single
         unaffiliated   party  and  (ii)  based  on  the  investigation  of  the
         Prosperity  Business Campus by the Company,  management is not aware of
         any material  factors  relating to the Prosperity  Business Campus that
         would cause this financial information not to be necessarily indicative
         of  future  operating  results  other  than  the  factors  specifically
         considered by the Company as described below.

         In the decision to acquire the Prosperity  Business Campus, the Company
         considered the competition from other commercial  property owners,  the
         location, the leases, the rental rates and the occupancy levels.

         The Company  has  reviewed  the  expenses  of the  Prosperity  Business
         Campus,  including salaries of on-site personnel,  utilities,  property
         taxes,  supplies,  insurance and repairs and  maintenance.  The Company
         expects  that  certain  operating   expenses  in  the  future  will  be
         consistent  with  those  reported  for 2000 and the nine  months  ended
         September 30, 2001.

2.       Summary of Significant Accounting Policies

         Revenue Recognition

         The Prosperity  Business  Campus leases space to tenants for which they
         charge minimum rents and receive  reimbursement  for certain  operating
         expenses.  The leases are  accounted  for as  operating  leases and are
         non-cancelable with varying terms and expiration dates. Recoveries from
         tenants are recognized as income in the period the applicable costs are
         accrued.

         Use of Estimates

         The  preparation  of the  statements  of certain  revenues  and certain
         operating expenses in conformity with accounting  principles  generally
         accepted in the United States requires management to make estimates and
         assumptions  that affect the  amounts  reported  in the  statements  of
         certain revenues and certain operating expenses and accompanying notes.
         Actual results could differ from those estimates.

                                       6



                         REPORT OF INDEPENDENT AUDITORS


To the Board of Directors
of PS Business Parks, Inc.


We have audited the  accompanying  combined  statement  of certain  revenues and
certain  operating  expenses of the Cornell Oaks Corporate Center (as defined in
Note 1) ("Statement") for the year ended December 31, 2000. The Statement is the
responsibility  of  the  Cornell  Oaks  Corporate   Center's   management.   Our
responsibility  is to express an opinion on the above mentioned  Statement based
on our audit.

We conducted our audit in accordance with auditing standards  generally accepted
in the United States. Those standards require that we plan and perform the audit
to obtain  reasonable  assurance about whether the Statement is free of material
misstatement.  An audit includes examining, on a test basis, evidence supporting
the amounts and disclosures in the Statement.  An audit also includes  assessing
the accounting principles used and significant estimates made by management,  as
well as evaluating the overall Statement presentation. We believe that our audit
provides a reasonable basis for our opinion.

The  accompanying  Statement was prepared for the purpose of complying  with the
rules and regulations of the Securities and Exchange Commission.

In our opinion,  the Statement presents fairly the combined certain revenues and
certain  operating  expenses of the Cornell Oaks  Corporate  Center for the year
ended  December 31, 2000, in conformity  with  accounting  principles  generally
accepted in the United States.



                                                               ERNST & YOUNG LLP



Los Angeles, California
December 7, 2001


                                       7


                          CORNELL OAKS CORPORATE CENTER
     Combined Statements of Certain Revenues and Certain Operating Expenses


                                          Nine months ended        Year ended
                                          September 30, 2001   December 31, 2000
                                        --------------------- ------------------
                                             (Unaudited)

Certain rental revenues...............    $    7,625,000        $   9,494,000
Certain operating expenses............        (1,758,000)          (2,341,000)
                                        --------------------- ------------------
Certain  rental  revenues  in  excess
     certain operating expenses.......    $    5,867,000        $   7,153,000
                                        ===================== ==================


                             See accompanying notes
                                       8


                          CORNELL OAKS CORPORATE CENTER
 Notes to Combined Statements of Certain Revenues and Certain Operating Expenses


1.       Background and Basis for Presentation

         The  accompanying  combined  statements of certain revenues and certain
         operating  expenses  include the accounts of the Cornell Oaks Corporate
         Center  located in Oregon and  acquired  by PS  Business  Parks,  Inc.,
         through its consolidated  partnership  (collectively referred to as the
         "Company") on November 20, 2001.  The  statements are prepared in order
         to comply  with  Rule  3.14 of  Regulation  S-X of the  Securities  and
         Exchange Commission.

         The  combined  statements  of certain  revenues  and certain  operating
         expenses  include only the accounts and  activities of the Cornell Oaks
         Corporate  Center.   Items  that  are  not  comparable  to  the  future
         operations  of the Cornell Oaks  Corporate  Center have been  excluded.
         Such  items  include  depreciation,   amortization,   management  fees,
         interest income,  professional fees,  miscellaneous income and straight
         line rent adjustments.

         An audited statement is being presented for the most recent fiscal year
         available instead of the three most recent years based on the following
         factors:  (i) the Cornell Oaks  Corporate  Center were  acquired from a
         single  unaffiliated  party and (ii) based on the  investigation of the
         Cornell Oaks Corporate  Center by the Company,  management is not aware
         of any material  factors  relating to the Cornell Oaks Corporate Center
         would cause this financial information not to be necessarily indicative
         of  future  operating  results  other  than  the  factors  specifically
         considered by the Company as described below.

         In the  decision to acquire  the Cornell  Oaks  Corporate  Center,  the
         Company  considered  the  competition  from other  commercial  property
         owners,  the location,  the leases,  the rental rates and the occupancy
         levels.

         The Company has reviewed  the  expenses of the Cornell  Oaks  Corporate
         Center,  including salaries of on-site personnel,  utilities,  property
         taxes,  supplies,  insurance and repairs and  maintenance.  The Company
         expects  that  certain  operating   expenses  in  the  future  will  be
         consistent  with  those  reported  for 2000 and the nine  months  ended
         September 30, 2001.

2.       Summary of Significant Accounting Policies

         Revenue Recognition

         The Cornell  Oaks  Corporate  Center  leases space to tenants for which
         they  charge  minimum  rents and  receive  reimbursements  for  certain
         operating expenses. The leases of the Cornell Oaks Corporate Center are
         accounted for as operating leases and are  non-cancelable  with varying
         terms and expiration  dates.  Recoveries from tenants are recognized as
         income in the period the applicable costs are accrued.

         Use of Estimates

         The  preparation  of the combined  statements  of certain  revenues and
         certain  operating  expenses in conformity with  accounting  principles
         generally  accepted in the United  States  requires  management to make
         estimates  and  assumptions  that  affect the  amounts  reported in the
         combined  statements of certain revenues and certain operating expenses
         and  accompanying   notes.  Actual  results  could  differ  from  those
         estimates.


                                       9


ITEM 7 (B)  PRO FORMA CONSOLIDATED FINANCIAL STATEMENTS (UNAUDITED)

The  following  unaudited  pro  forma  consolidated  financial  statements  were
prepared to reflect the  acquisition  of real estate  facilities  by PS Business
Parks, Inc., through its consolidated  partnership  (collectively referred to as
the "Company")  during the period of June 1, 2001 and November 20, 2001.  During
that period, the Company acquired 12 buildings known as the Prosperity  Business
Campus  and 12  buildings  known as the  Cornell  Oaks  Corporate  Center  at an
aggregate  purchase price of  approximately  $175.9 million.  The Company is not
affiliated with the sellers and the purchase price was established through arm's
length  negotiations.  The acquisitions were funded with the Company's  existing
cash balances and  borrowings  of $60 million from its unsecured  line of credit
with Wells Fargo Bank.

In addition to  adjustments  to reflect the recently  acquired  properties,  pro
forma adjustments were made to reflect the following transactions:

         1.   On May 10, 2001 and June 18, 2001,  the Company  issued  1,840,000
              and 800,000  depositary  shares,  respectively,  each representing
              1/1,000 of a share of the  Company's 9 1/2%  Cumulative  Preferred
              Stock,   Series  D  at  $25.00  per  share.   Net  proceeds   were
              approximately  $64.3 million and were used for  investment in real
              estate.

         2.   On September 21, 2001, the Company  completed a private  placement
              of 2,120,000 preferred units with a preferred distribution rate of
              9 1/4%.  Net proceeds  were  approximately  $51.6 million and were
              used for investment in real estate.

The pro forma consolidated balance sheet at September 30, 2001 has been prepared
to reflect the subsequent acquisitions of commercial properties.

The pro forma  consolidated  statements  of  income  for the nine  months  ended
September  30,  2001 and the year ended  December  31,  2000 have been  prepared
assuming (i) the aforementioned  acquisitions of commercial  properties and (ii)
the aforementioned public offerings of depositary shares representing fractional
interest in preferred stock and the private  placement of preferred units, as if
all  such  transactions  were  consummated  at  the  beginning  of  the  periods
presented.  The operations of all property  acquisitions are based on historical
operating results.

The pro forma adjustments are based upon available  information and upon certain
assumptions  as set forth in the notes to the pro forma  consolidated  financial
statements that the Company believes is reasonable in the circumstances. The pro
forma consolidated financial statements and accompanying notes should be read in
conjunction  with the historical  financial  statements of the Company and other
documents filed with the Securities and Exchange  Commission (such as Form 8-K's
which  reference  property  acquisitions)  from time to time.  The following pro
forma  consolidated  financial  statements do not purport to represent  what the
Company's results of operations would actually have been if the transactions had
in fact  occurred  at the  beginning  of the dates  indicated  or to project the
Company's results of operations for any future date or period.


                                       10


                             PS BUSINESS PARKS, INC.
                      PRO FORMA CONSOLIDATED BALANCE SHEET
                               September 30, 2001
                                   (Unaudited)
                  (Amounts in thousands, except per share data)




                                                                                       Property
                                                                                     Acquisitions
                                                                  Historical           (Note 1)           Pro Forma
                           ASSETS                             ------------------ --------------------- --------------------
                           ------
                                                                                              
Cash and cash equivalents.................................      $        66,291    $       (27,500)      $      38,791
Marketable securities.....................................                8,657                  -               8,657
Real estate, net of accumulated depreciation..............              941,998             87,500           1,029,498
Receivables and other assets..............................               11,559                  -              11,559
                                                              ------------------ --------------------- --------------------
     Total assets.........................................      $     1,028,505    $        60,000       $   1,088,505
                                                              ================== ===================== ====================

            LIABILITIES AND SHAREHOLDERS' EQUITY
            ------------------------------------
Accrued and other liabilities.............................      $        35,202    $             -       $      35,202
Line of credit............................................                    -             60,000              60,000
Mortgage notes payable....................................               30,354                  -              30,354

Minority interests:
   Preferred units........................................              197,750                  -             197,750
   Common units...........................................              162,338                  -             162,338

Shareholders' equity:
   Preferred stock, $0.01  par value,   50,000,000  shares
      authorized, 4,840  shares  issued and outstanding at
      September 30, 2001..................................              121,000                  -             121,000
   Common  stock,  $0.01  par value,  100,000,000   shares
      authorized, 21,704,067 shares issued and outstanding
      at September 30, 2001...............................                  217                  -                 217
   Paid-in capital........................................              426,546                  -             426,546
   Cumulative net income..................................              162,134                  -             162,134
   Other comprehensive loss...............................                 (740)                 -                (740)
   Cumulative distributions...............................             (106,296)                 -            (106,296)
                                                              ------------------ --------------------- --------------------
       Total shareholders' equity.........................              602,861                  -             602,861
                                                              ------------------ --------------------- --------------------
   Total liabilities and shareholders' equity.............      $     1,028,505    $        60,000       $   1,088,505
                                                              ================== ===================== ====================

Book value per common share (Note 2)......................      $         22.20                          $       22.20
                                                              ================== ===================== ====================
Shares outstanding........................................               21,704                                 21,704
                                                              ================== ===================== ====================


         See Accompanying Notes to Pro Forma Consolidated Balance Sheet
                                       11


                             PS BUSINESS PARKS, INC.
                  NOTES TO PRO FORMA CONSOLIDATED BALANCE SHEET
                               September 30, 2001
                                   (Unaudited)


1.       Property Acquisitions
         ---------------------

         On November 20 2001,  the Company  acquired 12  buildings  known as the
         Cornell Oaks Corporate  Center from an  unaffiliated  third party at an
         aggregate cost of approximately $87.5 million.

         The  following  pro forma  adjustments  have been made to the pro forma
         consolidated balance sheet to reflect the aforementioned transaction as
         if these  properties  had been owned by the Company as of September 30,
         2001.

        o  Pro forma  adjustments  have  been made  to cash and cash equivalents
           to reflect:

           o The acquisition cost of the facilities acquired..    $(87,500,000)
           o Borrowings  from the  line of credit to  fund the
             acquisition......................................      60,000,000
                                                                 ---------------
                                                                  $(27,500,000)
                                                                 ===============

        o  A  pro forma  adjustment  has  been  made  to  real
           estate facilities  to reflect  the acquisition cost
           of the facilities acquired..........................   $ 87,500,000
                                                                 ===============
        o  A  pro forma  adjustment  has  been made to reflect
           borrowings  from  the  line  of  credit to fund the
           acquisition........................................    $ 60,000,000
                                                                 ===============

2.       Book value per common share
         ---------------------------

         Book value per  common  share has been  determined  by  dividing  total
         common  shareholders'  equity by the  outstanding  common  shares.  The
         following summarizes the common shares outstanding:

                                                                  Common shares
                                                                   outstanding
                                                                 ---------------
        o  Historical shares outstanding at September 30, 2001     21,704,000


                                       12


                             PS BUSINESS PARKS, INC.
                   PRO FORMA CONSOLIDATED STATEMENT OF INCOME
                  For the Nine Months Ended September 30, 2001
                                   (Unaudited)
                  (Amounts in thousands, except per share data)




                                                                                  Property          Other
                                                                                Acquisitions     Adjustments
                                                               Historical         (Note 1)         (Note 2)         Pro Forma
                                                            ----------------- --------------- ----------------- ------------------
                                                                                                    
               Revenues:
                  Rental income............................   $    121,964     $     12,983      $          -     $    134,947
                 Facility management fees primarily from
                    affiliates.............................            499                -                 -              499
                  Business services........................            308                -                 -              308
                  Interest and dividend income.............          1,671                -                 -            1,671
                                                            ----------------- --------------- ----------------- ------------------
                                                                   124,442           12,983                 -          137,425
                                                            ----------------- --------------- ----------------- ------------------
               Expenses:
                  Cost of operations.......................         32,852            3,302                 -           36,154
                  Cost of facility management..............            111                -                 -              111
                  Cost of business services................            460                -                 -              460
                  Depreciation and amortization............         30,058            2,453                 -           32,511
                  General and administrative...............          3,157                -                 -            3,157
                  Interest expense.........................            932                -             1,378            2,310
                                                            ----------------- --------------- ----------------- ------------------
                                                                    67,570            5,755             1,378           74,703
                                                            ----------------- --------------- ----------------- ------------------
               Income  (loss)  before  gain on real  estate
               investments and minority interest in income.         56,872            7,228            (1,378)          62,722
                  Gain on investment in Pacific Gulf
                  Properties, Inc..........................             15                -                 -               15
                                                            ----------------- --------------- ----------------- ------------------
               Income  (loss) before  minority  interest in
               income......................................         56,887            7,228            (1,378)          62,737
                  Minority interest in income - preferred           (9,696)               -            (3,541)         (13,237)
                  units....................................
                  Minority interest in income - common
                  units (Note 4)...........................        (10,047)          (1,764)            1,811           (9,999)
                                                            ----------------- --------------- ----------------- ------------------
               Net income (loss)...........................   $     37,144     $      5,464      $     (3,108)    $     39,501
                                                            ================= =============== ================= ==================

               Net income (loss) allocation:
                  Allocable to preferred shareholders......   $      6,014     $          -      $      2,504     $      8,518
                  Allocable to common shareholders.........         31,130            5,464            (5,612)          30,983
                                                            ----------------- --------------- ----------------- ------------------
                                                              $     37,144     $      5,464      $     (3,108)    $     39,501
                                                            ================= =============== ================= ==================
               Net income per common share (Note 3):
                    Basic..................................   $      1.38                                         $        1.37
                                                            =================                                   ==================
                    Diluted................................   $      1.37                                         $        1.37
                                                            =================                                   ==================

               Weighted average common shares outstanding
               (Note 3):
                    Basic..................................         22,610                                               22,610
                                                            =================                                   ==================
                    Diluted................................         22,685                                               22,685
                                                            =================                                   ==================



     See Accompanying Notes to Pro Forma Consolidated Statements of Income
                                       13


                             PS BUSINESS PARKS, INC.
                   PRO FORMA CONSOLIDATED STATEMENT OF INCOME
                      For the Year Ended December 31, 2000
                                   (Unaudited)
                  (Amounts in thousands, except per share data)




                                                                                  Property          Other
                                                                                Acquisitions     Adjustments
                                                               Historical         (Note 1)         (Note 2)         Pro Forma
                                                            ----------------- --------------- ----------------- ------------------
                                                                                                    
               Revenues:
                  Rental income............................   $    144,171     $     21,066      $          -     $    165,237
                 Facility management fees primarily from
                    affiliates.............................            581                -                 -              581
                  Business services........................            505                -                 -              505
                  Interest and dividend income.............          5,377                -                 -            5,377
                                                            ----------------- --------------- ----------------- ------------------
                                                                   150,634           21,066                 -          171,700
                                                            ----------------- --------------- ----------------- ------------------
               Expenses:
                  Cost of operations.......................         39,290            5,595                 -           44,885
                  Cost of facility management..............            111                -                 -              111
                  Cost of business services................            344                -                 -              344
                  Depreciation and amortization............         35,637            4,264                 -           39,901
                  General and administrative...............          3,954                -                 -            3,954
                  Interest expense.........................          1,481                -             1,838            3,319
                                                            ----------------- --------------- ----------------- ------------------
                                                                    80,817            9,859             1,838           92,514
                                                            ----------------- --------------- ----------------- ------------------
               Income  (loss)  before  gain on real  estate
               investments and minority interest in income.         69,817           11,207            (1,838)          79,186
                  Gain on disposition of real estate.......            256                -                 -              256
                  Gain on investment in Pacific Gulf
                  Properties, Inc..........................          7,849                -                 -            7,849
                                                            ----------------- --------------- ----------------- ------------------
               Income  (loss) before  minority  interest in
               income......................................         77,922           11,207            (1,838)          87,291
                  Minority interest in income - preferred          (12,185)               -            (4,903)         (17,088)
                  units....................................
                  Minority interest in income - common
                  units (Note 4)...........................        (14,556)          (2,690)            3,123          (14,123)
                                                            ----------------- --------------- ----------------- ------------------
               Net income..................................   $     51,181     $      8,517      $     (3,618)    $     56,080
                                                            ================= =============== ================= ==================
               Net income allocation:
                  Allocable to preferred shareholders......   $      5,088     $          -      $      6,270     $     11,358
                  Allocable to common shareholders.........         46,093            8,517            (9,888)          44,722
                                                            ----------------- --------------- ----------------- ------------------
                                                              $     51,181     $      8,517      $     (3,618)    $     56,080
                                                            ================= =============== ================= ==================
               Net income per common share (Note 3):
                    Basic..................................   $      1.98                                         $        1.92
                                                            =================                                   ==================
                    Diluted................................   $      1.97                                         $        1.91
                                                            =================                                   ==================

               Weighted average common shares outstanding
               (Note 3):
                    Basic..................................         23,284                                               23,284
                                                            =================                                   ==================
                    Diluted................................         23,365                                               23,365
                                                            =================                                   ==================



     See Accompanying Notes to Pro Forma Consolidated Statements of Income
                                       14


                             PS BUSINESS PARKS, INC.
              NOTES TO PRO FORMA CONSOLIDATED STATEMENTS OF INCOME
                  For the nine months ended September 30, 2001
                      and the year ended December 31, 2000
                                   (Unaudited)

1.       Property Acquisitions
         ---------------------

         The  following  pro forma  adjustments  have been made to  reflect  the
         operations of the newly acquired  properties as if such  properties had
         been owned and operated by the Company  throughout  the entire  periods
         presented:




                                                                              Nine months ended       Year ended
                                                                              September 30, 2001   December 31, 2000
                                                                            --------------------- ---------------------
                                                                                      (Amounts in thousands)
                                                                                            
        o   Rental income has been adjusted to reflect:
             o    the  pro  forma   rental   income  as  if  the  acquired
                  properties  were owned by the  Company  for the  periods
                  presented:
                     Prosperity Business Campus...........................    $        9,731        $       11,572
                     Cornell Oaks Corporate Center........................             7,625                 9,494
             o    the rental income of these  properties which are already
                  included in the Company's historical amounts............            (4,373)                    -
                                                                            --------------------- ---------------------
                                                                              $       12,983        $       21,066
                                                                            --------------------- ---------------------
        o   Cost of operations has been adjusted to reflect:
             o   the pro  forma  cost  of  operations  as if the  acquired
                 properties  were  owned by the  Company  for the  periods
                 presented:
                     Prosperity Business Campus...........................    $        2,625        $        3,254
                     Cornell Oaks Corporate Center........................             1,758                 2,341
             o   the cost of  operations  of these  properties  which  are
                 already included in the Company's historical amounts.....            (1,081)                    -
                                                                            --------------------- ---------------------
                                                                              $        3,302        $        5,595
                                                                            ===================== =====================

        o    A   pro    forma    adjustment  has  been made to reflect the
             incremental depreciation  expense of the acquired  properties
             as  if  they  were  owned  by  the  Company  for  the periods
             presented....................................................    $        2,453        $        4,264
                                                                            ===================== =====================
        o    Minority  interest  in income allocable to common unitholders
             has  been  adjusted   based  upon  its  pro   rata  ownership
             interest in the pro forma adjustments above...................    $       (1,764)       $       (2,690)
                                                                            ===================== =====================



                                       15



                             PS BUSINESS PARKS, INC.
              NOTES TO PRO FORMA CONSOLIDATED STATEMENTS OF INCOME
                  For the nine months ended September 30, 2001
                      and the year ended December 31, 2000
                                   (Unaudited)


2.    Other Pro Forma Adjustments
      ---------------------------



                                                                              Nine months ended          Year ended
                                                                              September 30, 2001     December 31, 2000
                                                                             ---------------------  --------------------
                                                                                      (Amounts in thousands,
                                                                                       except per share data)
                                                                                              
        o    Interest  expense has been adjusted to  reflect the interest
             expense  associated  with  the  line  of   credit  as if the
             borrowings   had   been   completed  at the beginning of the
             periods presented                                                $        1,378        $        1,838
                                                                             =====================  ====================

        o    Minority interest in income  -  preferred  has been adjusted
             to reflect the incremental preferred distributions as if the
             preferred unit  offering had been completed at the beginning
             of the periods presented....................................     $       (3,541)       $       (4,903)
                                                                             =====================  ====================

        o    Net  income  allocable to  preferred  shareholders  has been
             adjusted to reflect the  incremental  preferred dividends as
             if the  preferred   stock offering had been completed at the
             beginning of the periods presented..........................     $        2,504        $        6,270
                                                                             =====================  ====================

        o    Minority   interest     in    income  allocable   to  common
             unitholders  has  been  adjusted  based  upon  its pro  rata
             ownership interest in the above pro forma adjustments.......     $        1,811        $        3,123
                                                                             =====================  ====================



                                       16



                             PS BUSINESS PARKS, INC.
              NOTES TO PRO FORMA CONSOLIDATED STATEMENTS OF INCOME
                  For the nine months ended September 30, 2001
                      and the year ended December 31, 2000
                                   (Unaudited)

3.    Net income per common share has been computed as follows:
      ---------------------------------------------------------



                                                                              Nine months ended        Year ended
                                                                              September 30, 2001    December 31, 2000
                                                                            ---------------------  --------------------
                                                                                             
                                                                                     (Amounts in thousands,
                                                                                      except per share data)

        Historical net income allocable to common shareholders...........     $       31,130        $       46,093
                                                                            ====================== ====================
        Historical weighted average common shares - basic................             22,610                23,284
             Dilutive effect of stock options............................                 75                    81
                                                                            ---------------------  --------------------
        Historical weighted average common shares - diluted..............             22,685                23,365
                                                                            ====================== ====================
        Historical net income per common share - basic...................    $         1.38        $         1.98
        Historical net income per common share - diluted.................    $         1.37        $         1.97

        ---------------------------------------------------------------------------------------------------------------

        Pro forma net income allocable to common shareholders............     $       30,983        $       44,722
                                                                            ====================== ====================
        Pro forma weighted average common shares - basic.................             22,610                23,284
             Dilutive effect of stock options............................                 75                    81
                                                                            ---------------------  --------------------
        Pro forma weighted average common shares - diluted...............             22,685                23,365
                                                                            ====================== ====================
        Pro forma net income per common share - basic....................    $         1.37        $         1.92
        Pro forma net income per common share - diluted..................    $         1.37        $         1.91




                                       17



                             PS BUSINESS PARKS, INC.
              NOTES TO PRO FORMA CONSOLIDATED STATEMENTS OF INCOME
                  For the nine months ended September 30, 2001
                      and the year ended December 31, 2000
                                   (Uuaudited)


4.       Minority Interest
         -----------------

         Minority interest represents  ownership interests of common OP units in
         the  consolidated  Operating  Partnership  which  are not  owned by the
         Company.  The common OP units,  subject to  certain  conditions  of the
         Operating Partnership Agreement,  are convertible into common shares of
         the Company on a one-for-one  basis. The following table summarizes the
         ownership interests:




                                                                              Nine months ended           Year ended
                                                                              September 30, 2001     December 31, 2000
                                                                           ----------------------- ---------------------
                                                                                       (Amounts in thousands,
                                                                                        except per share data)
                                                                                             

        Pro forma weighted average common shares outstanding...........               22,610                23,284
        Pro  forma  weighted  average common OP units owned by minority
          minority interests...........................................                7,307                 7,363
                                                                           ----------------------- ---------------------
        Pro forma weighted average  common shares outstanding  assuming
        conversion of common OP units..................................               29,917                30,647
                                                                           ======================= =====================

        Percentage owned by common shareholders........................                75.6%                 76.0%
        Percentage owned by common unitholders.........................                24.4%                 24.0%
                                                                           ----------------------- ---------------------
             Total ownership interest..................................               100.0%                100.0%
                                                                           ======================= =====================



                                       18