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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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<SEC-DOCUMENT>0001034316-09-000001.txt : 20090730
<SEC-HEADER>0001034316-09-000001.hdr.sgml : 20090730
<ACCEPTANCE-DATETIME>20090730170636
ACCESSION NUMBER:		0001034316-09-000001
CONFORMED SUBMISSION TYPE:	4/A
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20090213
FILED AS OF DATE:		20090730
DATE AS OF CHANGE:		20090730

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			PIONEER NATURAL RESOURCES CO
		CENTRAL INDEX KEY:			0001038357
		STANDARD INDUSTRIAL CLASSIFICATION:	CRUDE PETROLEUM & NATURAL GAS [1311]
		IRS NUMBER:				752702753
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1206

	BUSINESS ADDRESS:	
		STREET 1:		200 WILLIAMS SQUARE WEST
		STREET 2:		5205 N OCONNOR BLVD
		CITY:			IRVING
		STATE:			TX
		ZIP:			75039
		BUSINESS PHONE:		9724449001

	MAIL ADDRESS:	
		STREET 1:		200 WILLIAMS SQUARE WEST
		STREET 2:		5205 N OCONNOR BLVD
		CITY:			IRVING
		STATE:			TX
		ZIP:			75039

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			SHEFFIELD SCOTT D
		CENTRAL INDEX KEY:			0001034316

	FILING VALUES:
		FORM TYPE:		4/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-13245
		FILM NUMBER:		09974534

	MAIL ADDRESS:	
		STREET 1:		5205 NORTH OCONNOR BLVD
		STREET 2:		SUITE 900
		CITY:			IRVING
		STATE:			TX
		ZIP:			75039
</SEC-HEADER>
<DOCUMENT>
<TYPE>4/A
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2009-02-13</periodOfReport>

    <dateOfOriginalSubmission>2009-02-18</dateOfOriginalSubmission>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001038357</issuerCik>
        <issuerName>PIONEER NATURAL RESOURCES CO</issuerName>
        <issuerTradingSymbol>PXD</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001034316</rptOwnerCik>
            <rptOwnerName>SHEFFIELD SCOTT D</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>5205 NORTH OCONNOR BLVD</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 200</rptOwnerStreet2>
            <rptOwnerCity>IRVING</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>75039</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chairman of the Board and CEO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>447196</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>22135</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>401(k)</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Phantom Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F2"/>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F3"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>37827</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>37827</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Retirement Savings Plan</value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Consists of shares beneficially owned as a result of reporting person's ownership of units in the Pioneer Natural Rsources USA, Inc. 401(k) Plan.</footnote>
        <footnote id="F2">Each share of phantom stock represents the right to receive one share of PXD common stock or the cash value thereof.</footnote>
        <footnote id="F3">This amendment is being filed for the purpose of amending this footnote 3 in its entirety to read as follows: 7,327 of the shares of phantom stock held following the reported transactions are payable in cash following the termination of the reporting person's employment with PXD, and the reporting person may transfer such shares of his phantom stock account into an alternative investment account at any time. The retirement plan investment reported herein and giving rise to the beneficial ownership of the remaining 30,500 shares of phantom stock is irrevocable and can not be reallocated or diversified; the portion of the plan assets that reflect this investment can only be distributed in shares of PXD common stock (at the time or times that the reporting person has elected under the plan).</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Mark H. Kleinman, Attorney-in-Fact for Scott D. Sheffield</signatureName>
        <signatureDate>2009-07-30</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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