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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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<SEC-DOCUMENT>0000015847-10-000013.txt : 20100726
<SEC-HEADER>0000015847-10-000013.hdr.sgml : 20100726
<ACCEPTANCE-DATETIME>20100726170952
ACCESSION NUMBER:		0000015847-10-000013
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20100726
FILED AS OF DATE:		20100726
DATE AS OF CHANGE:		20100726

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			BUTLER NATIONAL CORP
		CENTRAL INDEX KEY:			0000015847
		STANDARD INDUSTRIAL CLASSIFICATION:	AIRCRAFT [3721]
		IRS NUMBER:				410834293
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0430

	BUSINESS ADDRESS:	
		STREET 1:		19920 W 161ST ST
		CITY:			OLATHE
		STATE:			KS
		ZIP:			66062
		BUSINESS PHONE:		8167809595

	MAIL ADDRESS:	
		STREET 1:		19920 W 161ST ST
		CITY:			OLATHE
		STATE:			KS
		ZIP:			66062

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	NATIONAL CONNECTOR CORP
		DATE OF NAME CHANGE:	19701009

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			STEWART CLARK D
		CENTRAL INDEX KEY:			0001224583

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-01678
		FILM NUMBER:		10969860

	MAIL ADDRESS:	
		STREET 1:		15733 SHANNAN LANE
		CITY:			OLATHE
		STATE:			KS
		ZIP:			66062
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2010-07-26</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000015847</issuerCik>
        <issuerName>BUTLER NATIONAL CORP</issuerName>
        <issuerTradingSymbol>buks</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001224583</rptOwnerCik>
            <rptOwnerName>STEWART CLARK D</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>15733 SHANNAN LANE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>OLATHE</rptOwnerCity>
            <rptOwnerState>KS</rptOwnerState>
            <rptOwnerZipCode>66062</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>CEO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-07-26</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>915773</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>915773</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By 401(k) Plan</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2195390</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>20000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Spouse</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The reporting person has acquired 915,773 shares of Butler National Corporation common stock under the Butler National Corporation 401(k) Profit Sharing Plan.  These acquisitions are a result of the Company Matching Contributions contributed by the issuer pursuant to the &quot;company match&quot; feature of the plan.  Such shares are deemed beneficially owned by the insider.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Clark D. Stewart</signatureName>
        <signatureDate>2010-07-26</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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