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

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2008-10-13</periodOfReport>

    <issuer>
        <issuerCik>0001420413</issuerCik>
        <issuerName>North Asia Investment CORP</issuerName>
        <issuerTradingSymbol>NHR</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001132413</rptOwnerCik>
            <rptOwnerName>MILLENCO, L.L.C.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O MILLENNIUM MANAGEMENT LLC</rptOwnerStreet1>
            <rptOwnerStreet2>666 FIFTH AVENUE, 8TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10103-0899</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001273087</rptOwnerCik>
            <rptOwnerName>MILLENNIUM MANAGEMENT, L.L.C.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>666 FIFTH AVENUE, 8TH FLOOR</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10103-0899</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>May be deemed a group member.</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001017456</rptOwnerCik>
            <rptOwnerName>ENGLANDER ISRAEL A</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O MILLENNIUM MANAGEMENT, L.L.C.</rptOwnerStreet1>
            <rptOwnerStreet2>666 FIFTH AVENUE, 8TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10103-0899</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>May be deemed a group member.</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2008-10-13</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>2700</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>8.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>937680</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F4"/>
                    <footnoteId id="F5"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">As of the date of this filing, Millenco LLC, a Delaware limited liability company (&quot;Millenco&quot;), is the beneficial owner of 937,680 shares of common stock, par value $0.0001 per share (&quot;Common Stock&quot;) of North Asia Investment Corporation (the &quot;Issuer&quot;) of which 608,480 are a constituent part of the Issuer's units (&quot;Units&quot;), of which Millenco holds 608,480.  Each Unit consists of one share of Common Stock and one warrant to purchase the Issuer's Common Stock (&quot;Warrant&quot;).</footnote>
        <footnote id="F2">Each Warrant entitles the holder to purchase one share of the Issuer's Common Stock at a price of $7.50. Each Warrant will become exercisable on the later of the Issuer's consummation of a business combination and July 23, 2009, provided that the Issuer has an effective registration statement covering the Common Sock issuable upon exercise of the Warrants and a current prospectus is available.  The Warrants will expire on July 22, 2013, or earlier upon redemption.  As of the date of this filing, the Issuer has not completed a business combination, and thus, the Warrants are not currently exercisable.</footnote>
        <footnote id="F3">In addition to the 608,480 Warrants held by Millenco as a constituent part of the Units, Millenco holds an additional 265,100 Warrants, which are also not currently exercisable.</footnote>
        <footnote id="F4">Millennium Management LLC, a Delaware limited liability company (&quot;Millennium Management&quot;), is the manager of Millenco, and consequently may be deemed to have shared voting control and investment discretion over securities owned by Millenco. Israel A. Englander (&quot;Mr. Englander&quot;) is the managing member of Millennium Management. As a result, Mr. Englander may be deemed to have shared voting control and investment discretion over securities deemed to be beneficially owned by Millennium Management. The foregoing should not be construed in and of itself as an admission by Millennium Management or Mr. Englander as to beneficial ownership of the shares owned by Millenco.</footnote>
        <footnote id="F5">The foregoing should not be construed in and of itself as an admission by Millennium Management or Mr. Englander as to beneficial ownership of the shares owned by Millenco.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Mark Meskin, Chief Executive Officer</signatureName>
        <signatureDate>2008-10-14</signatureDate>
    </ownerSignature>
</ownershipDocument>
