<SEC-DOCUMENT>0001209191-15-029223.txt : 20150325
<SEC-HEADER>0001209191-15-029223.hdr.sgml : 20150325
<ACCEPTANCE-DATETIME>20150325165558
ACCESSION NUMBER:		0001209191-15-029223
CONFORMED SUBMISSION TYPE:	4/A
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20150316
FILED AS OF DATE:		20150325
DATE AS OF CHANGE:		20150325

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:			1228

	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

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			RATCLIFFE DAVID M
		CENTRAL INDEX KEY:			0001195258

	FILING VALUES:
		FORM TYPE:		4/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-08022
		FILM NUMBER:		15725227

	MAIL ADDRESS:	
		STREET 1:		241 RALPH MCGILL BLVD
		STREET 2:		BIN 10115
		CITY:			ATLANTA
		STATE:			GA
		ZIP:			30308
</SEC-HEADER>
<DOCUMENT>
<TYPE>4/A
<SEQUENCE>1
<FILENAME>doc4a.xml
<DESCRIPTION>FORM 4/A SUBMISSION
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2015-03-16</periodOfReport>

    <dateOfOriginalSubmission>2015-03-18</dateOfOriginalSubmission>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001195258</rptOwnerCik>
            <rptOwnerName>RATCLIFFE DAVID M</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>500 WATER STREET</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>JACKSONVILLE</rptOwnerCity>
            <rptOwnerState>FL</rptOwnerState>
            <rptOwnerZipCode>32202</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>220777</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>CSX Corporation Directors Deferred Compensation Plan</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Phantom Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F3"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2015-03-13</value>
                <footnoteId id="F4"/>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>10984</value>
                    <footnoteId id="F5"/>
                    <footnoteId id="F6"/>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F7"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F3"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>10984</value>
                    <footnoteId id="F5"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>10984</value>
                    <footnoteId id="F5"/>
                    <footnoteId id="F6"/>
                    <footnoteId id="F8"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>CSX Corporation Directors Deferred Compensation Plan</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">1,029 shares credited since date of original filing as a result of dividend reinvestment.</footnote>
        <footnote id="F2">By Trustee, CSX Directors Deferred Compensation Plan (the &quot;Plan&quot;).  The shares are payable after the reporting person ceases to be a director or otherwise pursuant to the terms of the Plan.</footnote>
        <footnote id="F3">Each unit of phantom stock is the economic equivalent of one share of Company common stock.  Units of phantom stock become payable, in cash, consistent with the Reporting Person's distribution election made at the time of deferral.</footnote>
        <footnote id="F4">As a result of the loss of the historical transaction details, the Reporting Person is unable to provide the date of the earliest transaction.  Accordingly, the date of the last previously reported transaction was utilized.</footnote>
        <footnote id="F5">Includes units of phantom stock credited to the Reporting Person's account as a result of the dividend reinvestment feature of the CSX Corporation Directors Deferred Compensation Plan (the &quot;Plan&quot;).</footnote>
        <footnote id="F6">Prior to 2007, the Reporting Person deferred a portion of his cash compensation under the Plan, which was notionally invested into a fund that tracks the value of CSX common stock.  At the time of the Reporting Person's initial election and subsequent deferrals, the Company relied upon a third-party vendor to document the timing of each deferral.  The Company has since stopped using such vendor.  In the process of moving this responsibility to a new third-party, the information regarding the timing of deferrals was lost.  Since 2007, the Reporting Person has not deferred any portion of his cash compensation into investments that could be deemed phantom stock other than as a result of dividend reinvestments under the Plan.</footnote>
        <footnote id="F7">Price of each unit of phantom stock was determined at the time of the applicable deferral pursuant to the Plan; therefore, the units have been acquired at various prices.  The prices at which the units were acquired is indeterminable.</footnote>
        <footnote id="F8">As the result of an administrative oversight by the Company, the Reporting Person did not timely file a Form 4 for any of the Reporting Person's cash deferrals under the Plan.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Mark D. Austin, Attorney-in-Fact</signatureName>
        <signatureDate>2015-03-25</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
