FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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(Print or Type Responses)

1. Name and Address of Reporting Person *   SEXTON MARK S 2. Date of Event Requiring Statement (Month/Day/Year) 09/28/2004 3. Issuer Name and Ticker or Trading Symbol PIONEER NATURAL RESOURCES CO [PXD] (Last) (First) (Middle) 5205 N O'CONNOR BLVD, SUITE 200 4. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director _____ 10% Owner _____ Officer (give title below) _____ Other (specify below) 5. If Amendment, Date Original Filed(Month/Day/Year) 09/30/2004 (Street) IRVING, TX 75039 6. Individual or Joint/Group Filing(Check Applicable Line) _X_ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Beneficially Owned

1.Title of Security (Instr. 4) 2. Amount of Securities Beneficially Owned (Instr. 4) 3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5) 4. Nature of Indirect Beneficial Ownership (Instr. 5) Common Stock 175,012 (1) D   Common Stock 4,165 (2) I IRA Common Stock 2,641 (3) I by Spouse

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.			SEC 1473 (7-02)
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Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
SEXTON MARK S 5205 N O'CONNOR BLVD SUITE 200 IRVING, TX 75039	  X	Â	Â	Â

Signatures

Mark H. Kleinman, Attorney-in-Fact		04/10/2007
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 5(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	18,029 shares were omitted from the number of securities beneficially owned directly by the reporting person, as reported on his original Form 3, and were also omitted from all subsequent Forms 4 filed by the reporting person. As of September 28, 2004, the reporting person directly owned 175,012 shares of common stock.
(2)	On September 28, 2004, the reporting person indirectly owned only 4,165 shares of common stock, held in an IRA. The number of shares reported on the reporting person's original Form 3 was incorrect, and the IRA balance was also reported incorrectly on all subsequent Form 4 filings.
(3)	These shares were omitted from the reporting person's original Form 3, and were also omitted from the subsequent Forms 4 filed by the reporting person.

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