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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>0000277948-05-000080.txt : 20051219
<SEC-HEADER>0000277948-05-000080.hdr.sgml : 20051219
<ACCEPTANCE-DATETIME>20051219145015
ACCESSION NUMBER:		0000277948-05-000080
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20051215
FILED AS OF DATE:		20051219
DATE AS OF CHANGE:		20051219

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Breaux John B
		CENTRAL INDEX KEY:			0001326327

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-08022
		FILM NUMBER:		051272239

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		904-366-4242

	MAIL ADDRESS:	
		STREET 1:		CSX CORPORATION
		STREET 2:		500 WATER STREET, C160
		CITY:			JACKSONVILLE
		STATE:			FL
		ZIP:			32202

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			CSX CORP
		CENTRAL INDEX KEY:			0000277948
		STANDARD INDUSTRIAL CLASSIFICATION:	RAILROADS, LINE-HAUL OPERATING [4011]
		IRS NUMBER:				621051971
		STATE OF INCORPORATION:			VA
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		500 WATER STREET
		STREET 2:		15TH FLOOR
		CITY:			JACKSONVILLE
		STATE:			FL
		ZIP:			32202
		BUSINESS PHONE:		9043593200

	MAIL ADDRESS:	
		STREET 1:		500 WATER STREET
		STREET 2:		15TH FLOOR
		CITY:			JACKSONVILLE
		STATE:			FL
		ZIP:			32202
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2005-12-15</periodOfReport>

    <issuer>
        <issuerCik>0000277948</issuerCik>
        <issuerName>CSX CORP</issuerName>
        <issuerTradingSymbol>CSX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001326327</rptOwnerCik>
            <rptOwnerName>Breaux John B</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>PATTON BOGGS, LLP</rptOwnerStreet1>
            <rptOwnerStreet2>2550 M. STREET NW</rptOwnerStreet2>
            <rptOwnerCity>WASHINGTON</rptOwnerCity>
            <rptOwnerState>DC</rptOwnerState>
            <rptOwnerZipCode>20037</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2005-12-15</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>190.5875</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>49.19</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3656</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Trustee</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Exempt payment of director's fees and/or annual retainer in the form of CSX Common Stock pursuant to the CSX Corporation Stock Plan for Directors. The units are payable in cash after the reporting person ceases to be a director or otherwise pursuant to the terms of the CSX Corporation Stock Plan for Directors.</footnote>
        <footnote id="F2">By Trustee, CSX Corporation Stock Plan for Directors.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>John B. Breaux by Gordon F. Bailey, Attorney-in-Fact</signatureName>
        <signatureDate>2005-12-19</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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