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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>0000007332-04-000009.txt : 20040120
<SEC-HEADER>0000007332-04-000009.hdr.sgml : 20040119
<ACCEPTANCE-DATETIME>20040120114130
ACCESSION NUMBER:		0000007332-04-000009
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20040116
FILED AS OF DATE:		20040120

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			SOUTHWESTERN ENERGY CO
		CENTRAL INDEX KEY:			0000007332
		STANDARD INDUSTRIAL CLASSIFICATION:	CRUDE PETROLEUM & NATURAL GAS [1311]
		IRS NUMBER:				710205415
		STATE OF INCORPORATION:			AR
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		2350 N. SAM HOUSTON PARKWAY EAST
		STREET 2:		SUITE 300
		CITY:			HOUSTON
		STATE:			TX
		ZIP:			77032
		BUSINESS PHONE:		2816184700

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	ARKANSAS WESTERN GAS CO
		DATE OF NAME CHANGE:	19790917

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			SCHARLAU CHARLES E
		CENTRAL INDEX KEY:			0001103811

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-08246
		FILM NUMBER:		04531595

	BUSINESS ADDRESS:	
		STREET 1:		2350 N. SAM HOUSTON PARKWAY EAST
		STREET 2:		SUITE 300
		CITY:			HOUSTON
		STATE:			TX
		ZIP:			77032
		BUSINESS PHONE:		2816184700

	MAIL ADDRESS:	
		STREET 1:		2350 N. SAM HOUSTON PARKWAY EAST
		STREET 2:		SUITE 300
		CITY:			HOUSTON
		STATE:			TX
		ZIP:			77032
</SEC-HEADER>
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<TYPE>4
<SEQUENCE>1
<FILENAME>c0001103811d20040120f4f.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<ownershipDocument><schemaVersion>X0201</schemaVersion>    <documentType>4</documentType><periodOfReport>2004-01-16</periodOfReport><notSubjectToSection16>0</notSubjectToSection16><issuer><issuerCik>0000007332</issuerCik><issuerName>SOUTHWESTERN ENERGY CO</issuerName>        <issuerTradingSymbol>SWN</issuerTradingSymbol></issuer><reportingOwner><reportingOwnerId><rptOwnerCik>0001103811</rptOwnerCik><rptOwnerName>SCHARLAU CHARLES E</rptOwnerName></reportingOwnerId><reportingOwnerAddress><rptOwnerStreet1>2350 N. SAM HOUSTON PARKWAY EAST</rptOwnerStreet1><rptOwnerStreet2>SUITE 300</rptOwnerStreet2><rptOwnerCity>HOUSTON</rptOwnerCity><rptOwnerState>TX</rptOwnerState><rptOwnerZipCode>77032</rptOwnerZipCode><rptOwnerStateDescription></rptOwnerStateDescription></reportingOwnerAddress><reportingOwnerRelationship><isDirector>1</isDirector><isOfficer>0</isOfficer><isTenPercentOwner>0</isTenPercentOwner><isOther>0</isOther><officerTitle></officerTitle><otherText></otherText></reportingOwnerRelationship></reportingOwner
><nonDerivativeTable><nonDerivativeTransaction><securityTitle><value>Common Stock</value></securityTitle><transactionDate><value>2004-01-16</value></transactionDate><deemedExecutionDate></deemedExecutionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>M</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionTimeliness><value></value></transactionTimeliness><transactionAmounts><transactionShares><value>20000</value></transactionShares><transactionPricePerShare><value>14.625</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>138124</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value></value></natureOfOwnership></ownershipNature></nonDerivativeTransaction><nonDerivat
iveTransaction><securityTitle><value>Common Stock</value></securityTitle><transactionDate><value>2004-01-16</value></transactionDate><deemedExecutionDate></deemedExecutionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>S</transactionCode><equitySwapInvolved>0</equitySwapInvolved><footnoteId id="F1"/></transactionCoding><transactionTimeliness><value></value></transactionTimeliness><transactionAmounts><transactionShares><value>18100</value></transactionShares><transactionPricePerShare><value>22.3</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>D</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>120024</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value></value></natureOfOwnership></ownershipNature></nonDerivativeTransaction><nonDerivativeTransactio
n><securityTitle><value>Common Stock</value></securityTitle><transactionDate><value>2004-01-16</value></transactionDate><deemedExecutionDate></deemedExecutionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>S</transactionCode><equitySwapInvolved>0</equitySwapInvolved><footnoteId id="F1"/></transactionCoding><transactionTimeliness><value></value></transactionTimeliness><transactionAmounts><transactionShares><value>1900</value></transactionShares><transactionPricePerShare><value>22.74</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>D</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>118124</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value></value></natureOfOwnership></ownershipNature></nonDerivativeTransaction><nonDerivativeHolding><securityTitle>
<value>Common Stock</value></securityTitle><postTransactionAmounts><sharesOwnedFollowingTransaction><value>1000</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>I</value></directOrIndirectOwnership><natureOfOwnership><value>By spouse</value></natureOfOwnership></ownershipNature></nonDerivativeHolding></nonDerivativeTable><derivativeTable><derivativeTransaction><securityTitle><value>Stock Options (Right to buy)</value></securityTitle><conversionOrExercisePrice><value>14.625</value></conversionOrExercisePrice><transactionDate><value>2004-01-16</value></transactionDate><deemedExecutionDate></deemedExecutionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>M</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>20000</value></transactionShares><transactionPricePerShare><value>0</value></transactionPricePerShare><transactionAcquiredDisposedCo
de><value>D</value></transactionAcquiredDisposedCode></transactionAmounts><exerciseDate><value>2000-12-14</value></exerciseDate><expirationDate><value>2004-12-14</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>20000</value></underlyingSecurityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>60000</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value></value></natureOfOwnership></ownershipNature></derivativeTransaction></derivativeTable><footnotes><footnote id="F1">The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on September 11, 2003, when not in possession of material nonpublic information.</footnote></footnotes><ownerSignature><signatureName>Kathy Harriell, Attorney 
in Fact for Charles E. Scharlau</signatureName><signatureDate>2004-01-20</signatureDate></ownerSignature></ownershipDocument>

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