<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2017-02-24</periodOfReport>

    <dateOfOriginalSubmission>2017-02-28</dateOfOriginalSubmission>

    <notSubjectToSection16>false</notSubjectToSection16>

    <issuer>
        <issuerCik>0000714603</issuerCik>
        <issuerName>DST SYSTEMS INC</issuerName>
        <issuerTradingSymbol>DST</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001281236</rptOwnerCik>
            <rptOwnerName>BURKE EDMUND J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1290 BROADWAY, SUITE 1100</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>DENVER</rptOwnerCity>
            <rptOwnerState>CO</rptOwnerState>
            <rptOwnerZipCode>80203</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>false</isDirector>
            <isOfficer>true</isOfficer>
            <isTenPercentOwner>false</isTenPercentOwner>
            <isOther>false</isOther>
            <officerTitle>President of Subsidiary</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2017-02-24</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>false</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>20</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3407</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">On February 28, 2017, the Reporting Person filed a Form 4 reporting the number of shares of common stock that would vest on the March 10, 2017 vesting of performance stock units (PSUs) plus the number of shares of common stock accrued as a result of dividend equivalent rights paid by the Company pursuant to the terms of the award. The award was granted on February 25, 2014 for the 2014-2016 performance period. The total number of shares reported should have been 3,397 instead of 3,387. Due to the two for one stock split on June 8, 2017, additional reported shares would now be an additional 20 shares. These under reported shares were also excluded in the direct ownership totals on four subsequent Form 4s filed by the Reporting Person on March 14, 2017, June 12, 2017, September 11, 2017, and December 12, 2017. As of January 31, 2018, Reporting Persons total direct ownership is 32,119 shares.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Randall D. Young for Edmund J. Burke by power of attorney</signatureName>
        <signatureDate>2018-01-31</signatureDate>
    </ownerSignature>
</ownershipDocument>
