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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2018-04-26</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001293613</issuerCik>
        <issuerName>Kayne Anderson MLP Investment CO</issuerName>
        <issuerTradingSymbol>KYN</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000005272</rptOwnerCik>
            <rptOwnerName>AMERICAN INTERNATIONAL GROUP INC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>175 WATER STREET</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10038</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>See Remarks</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>4.38% Series W Senior Unsecured Notes due May 26, 2018</value>
            </securityTitle>
            <transactionDate>
                <value>2018-04-26</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>6820000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>6925380.37</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <valueOwnedFollowingTransaction>
                    <value>0.00</value>
                </valueOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Held through subsidiaries</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>3.57% Series FF Senior Unsecured Notes due April 16, 2023</value>
            </securityTitle>
            <postTransactionAmounts>
                <valueOwnedFollowingTransaction>
                    <value>9000000.00</value>
                </valueOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Held through subsidiaries</value>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>3.67% Series GG Senior Unsecured Notes due April 16, 2025</value>
            </securityTitle>
            <postTransactionAmounts>
                <valueOwnedFollowingTransaction>
                    <value>10000000.00</value>
                </valueOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Held through subsidiaries</value>
                    <footnoteId id="F4"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>3.93% Series KK Senior Unsecured Notes due July 30, 2024</value>
            </securityTitle>
            <postTransactionAmounts>
                <valueOwnedFollowingTransaction>
                    <value>20000000.00</value>
                </valueOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Held through subsidiaries</value>
                    <footnoteId id="F5"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>2.89% Series LL Senior Unsecured Notes due October 29, 2020</value>
            </securityTitle>
            <postTransactionAmounts>
                <valueOwnedFollowingTransaction>
                    <value>33000000.00</value>
                </valueOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Held through subsidiaries</value>
                    <footnoteId id="F6"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>3.26% Series MM Senior Unsecured Notes due October 29, 2022</value>
            </securityTitle>
            <postTransactionAmounts>
                <valueOwnedFollowingTransaction>
                    <value>10000000.00</value>
                </valueOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Held through subsidiaries</value>
                    <footnoteId id="F7"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>3.46% Series OO Senior Unsecured Notes due October 29, 2024</value>
            </securityTitle>
            <postTransactionAmounts>
                <valueOwnedFollowingTransaction>
                    <value>15000000.00</value>
                </valueOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Held through subsidiaries</value>
                    <footnoteId id="F8"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Series H Mandatory Redeemable Preferred Shares</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>800000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Held through subsidiaries</value>
                    <footnoteId id="F9"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Series I Mandatory Redeemable Preferred Shares</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>240000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Held through subsidiaries</value>
                    <footnoteId id="F10"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The 4.38% Series W Senior Unsecured Notes due May 26, 2018 (the &quot;Series W Notes&quot;) were called for redemption by the issuer at a price equal to the principal amount of $6,820,000 of the redeemed securities plus accrued interest of $105,380.37 (the &quot;Redemption&quot;).</footnote>
        <footnote id="F2">Prior to the Redemption, The Variable Annuity Life Insurance Company (&quot;VALIC&quot;), an indirectly wholly owned subsidiary of American International Group, Inc. (&quot;AIG&quot;), directly held the Series W Notes. Prior to the Redemption, AIG was an indirect beneficial owner of the Series W Notes.</footnote>
        <footnote id="F3">American Home Assurance Company (&quot;AHAC&quot;), an indirect wholly owned subsidiary of AIG, and VALIC directly hold $4,000,000.00 principal amount and $5,000,000.00 principal amount, respectively, of the 3.57% Series FF Senior Unsecured Notes due April 16, 2023 (the &quot;Series FF Notes&quot;). AIG is an indirect beneficial owner of the Series FF Notes.</footnote>
        <footnote id="F4">Eaglestone Reinsurance Company (&quot;ERC&quot;), an indirect wholly owned subsidiary of AIG, and VALIC directly hold $2,300,000.00 principal amount and $7,700,000.00 principal amount, respectively, of the 3.67% Series GG Senior Unsecured Notes due April 16, 2025 (the &quot;Series GG Notes&quot;). AIG is an indirect beneficial owner of the Series GG Notes.</footnote>
        <footnote id="F5">AHAC and The United States Life Insurance Company in the City of New York (&quot;USLIC&quot;), also an indirect wholly owned subsidiary of AIG, directly hold $6,775,000.00 principal amount and $13,225,000.00 principal amount, respectively, of the 3.93% Series KK Senior Unsecured Notes due July 30, 2024 (the &quot;Series KK Notes&quot;). AIG is an indirect beneficial owner of the Series KK Notes.</footnote>
        <footnote id="F6">AHAC, Lexington Insurance Company (&quot;Lexington&quot;), also an indirectly wholly owned subsidiary of AIG, and National Union Fire Insurance Company of Pittsburgh, PA (&quot;NUF&quot;), also an indirectly wholly owned subsidiary of AIG, directly hold $16,014,900.00 principal amount, $985,100.00 principal amount and $16,000,000.00 principal amount, respectively, of the 2.89% Series LL Senior Unsecured Notes due October 29, 2020 (the &quot;Series LL Notes&quot;). AIG is an indirect beneficial owner of the Series LL Notes.</footnote>
        <footnote id="F7">AHAC, Lexington and NUF directly hold $4,701,500.00 principal amount, $298,500.00 principal amount and $5,000,000.00 principal amount, respectively, of the 3.26% Series MM Senior Unsecured Notes due October 29, 2022 (the &quot;Series MM Notes&quot;). AIG is an indirect beneficial owner of the Series MM Notes.</footnote>
        <footnote id="F8">American General Life Insurance Company (&quot;AGLIC&quot;) and Lexington directly hold $14,750,000.00 principal amount and $250,000.00 principal amount, respectively, of the 3.46% Series OO Senior Unsecured Notes due October 29, 2024 (the &quot;Series OO Notes&quot;). AIG is an indirect beneficial owner of the Series OO Notes.</footnote>
        <footnote id="F9">AGLIC and AHAC directly hold 532,000 shares and 268,000 shares, respectively, of the Series H Mandatory Redeemable Preferred Shares (the &quot;Series H MRPS&quot;). AIG is an indirect beneficial owner of the Series H MRPS.</footnote>
        <footnote id="F10">AHAC and VALIC directly hold 80,000 shares and 160,000 shares, respectively, of the Series I Mandatory Redeemable Preferred Shares (the &quot;Series I MRPS&quot;). AIG is an indirect beneficial owner of the Series I MRPS.</footnote>
    </footnotes>

    <remarks>Filed pursuant to Section 30(h) of the Investment Company Act of 1940.</remarks>

    <ownerSignature>
        <signatureName>/s/ Geoffrey N. Cornell, Authorized Person</signatureName>
        <signatureDate>2018-04-26</signatureDate>
    </ownerSignature>
</ownershipDocument>
