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

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2006-06-09</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001001111</issuerCik>
        <issuerName>US GLOBAL NANOSPACE  INC</issuerName>
        <issuerTradingSymbol>usga</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001354336</rptOwnerCik>
            <rptOwnerName>CRONIN KEVIN</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>2533 NORTH CARSON STREET</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 5107</rptOwnerStreet2>
            <rptOwnerCity>CARSON CITY</rptOwnerCity>
            <rptOwnerState>NV</rptOwnerState>
            <rptOwnerZipCode>89706</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chief Financial Officer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2006-06-09</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>443263</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.047</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1443263</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0.06</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2006-01-30</value>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <value>2013-01-30</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>2500000</value>
                    <footnoteId id="F2"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2500000</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">These shares constitute base salary pursuant to the terms of the Employment Agreement between the issuer and Mr. Cronin, dated January 7, 2006.</footnote>
        <footnote id="F2">These shares vest upon certain milestones as follows: 1,000,000 shares upon the closing of an equity financing of the issuer with gross proceeds of at least $2,000,000; 500,000 shares upon receipt of purchase order accepted by the issuer, or the execution by the issuer of an agreement, for the MAPSANDS technology or other products that has a value to the issuer of no less than $1,000,000; 500,000 shares upon receipt of purchase order accepted by the issuer, or the execution by the issuer of an agreement for the MAPSANDS technology or other products that has a value to the issuer of no less than $5,000,000; and 500,000 shares if the issuer shows positive cash flow for two consecutive quarters without further dilution of its common stock, excluding shares of common stock issued pursuant to equity compensation plans.</footnote>
        <footnote id="F3">1,000,000 of these shares are not fully vested and vest in equal increments on the last day of each month commencing on January 31, 2006 and ending on December 31, 2006.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Kevin C. Cronin</signatureName>
        <signatureDate>2006-06-14</signatureDate>
    </ownerSignature>
</ownershipDocument>
