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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 N/HyT7DRwf/U/mZA2KwKv1UGH+jDOv89VPL/KQgbBafI6/wcNzrrCVyWTdiuxG15
 rYGr5tOTldnjs2zTLp/h5g==

<SEC-DOCUMENT>0001209191-03-024443.txt : 20031003
<SEC-HEADER>0001209191-03-024443.hdr.sgml : 20031003
<ACCEPTANCE-DATETIME>20031003094506
ACCESSION NUMBER:		0001209191-03-024443
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20031001
FILED AS OF DATE:		20031003

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			VILLERS DONALD E
		CENTRAL INDEX KEY:			0001223993

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-32561
		FILM NUMBER:		03926344

	BUSINESS ADDRESS:	
		STREET 1:		15985 EAST HIGH STREET
		STREET 2:		P.O. BOX 35
		CITY:			MIDDLEFIELD
		STATE:			OH
		ZIP:			44062-9263

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MIDDLEFIELD BANC CORP
		CENTRAL INDEX KEY:			0000836147
		STANDARD INDUSTRIAL CLASSIFICATION:	STATE COMMERCIAL BANKS [6022]
		IRS NUMBER:				341585111
		STATE OF INCORPORATION:			OH

	BUSINESS ADDRESS:	
		STREET 1:		15985 E HIGH ST
		STREET 2:		P O BOX 35
		CITY:			MIDDLEFILED
		STATE:			OH
		ZIP:			44062-9263
		BUSINESS PHONE:		4406321666

	MAIL ADDRESS:	
		STREET 1:		15985 EAST HIGH STREET
		STREET 2:		P O BOX 35
		CITY:			MIDDLEFIELD
		STATE:			OH
		ZIP:			44062-9263
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc4.xml
<DESCRIPTION>FORM 4 SUBMISSION
<TEXT>
<XML>
<?xml version="1.0"?><ownershipDocument><schemaVersion>X0201</schemaVersion>    <documentType>4</documentType><periodOfReport>2003-10-01</periodOfReport><notSubjectToSection16>0</notSubjectToSection16><issuer><issuerCik>0000836147</issuerCik><issuerName>MIDDLEFIELD BANC CORP</issuerName>        <issuerTradingSymbol>MBCN</issuerTradingSymbol></issuer><reportingOwner><reportingOwnerId><rptOwnerCik>0001223993</rptOwnerCik><rptOwnerName>VILLERS DONALD E</rptOwnerName></reportingOwnerId><reportingOwnerAddress><rptOwnerStreet1>15985 EAST HIGH STREET</rptOwnerStreet1><rptOwnerStreet2>P. O. BOX 35</rptOwnerStreet2><rptOwnerCity>MIDDLEFIELD</rptOwnerCity><rptOwnerState>OH</rptOwnerState><rptOwnerZipCode>44062</rptOwnerZipCode><rptOwnerStateDescription></rptOwnerStateDescription></reportingOwnerAddress><reportingOwnerRelationship><isDirector>1</isDirector><isOfficer>0</isOfficer><isTenPercentOwner>0</isTenPercentOwner><isOther>0</isOther></reportingOwnerRelationship></reportingOwner><nonDerivativeTable><nonDerivativeT
ransaction><securityTitle><value>Common Stock</value></securityTitle><transactionDate><value>2003-10-01</value></transactionDate><deemedExecutionDate></deemedExecutionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>M</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionTimeliness><value></value></transactionTimeliness><transactionAmounts><transactionShares><value>150</value></transactionShares><transactionPricePerShare><value>22.86</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>5686.5071</value><footnoteId id="F1" /></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value><footnoteId id="F2" /></directOrIndirectOwnership></ownershipNature></nonDerivativeTransaction><nonDerivativeHolding><securityTitle><value>Common Stock<
/value></securityTitle><postTransactionAmounts><sharesOwnedFollowingTransaction><value>1585</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership></ownershipNature></nonDerivativeHolding><nonDerivativeHolding><securityTitle><value>Common Stock</value></securityTitle><postTransactionAmounts><sharesOwnedFollowingTransaction><value>649.9135</value><footnoteId id="F1" /></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>I</value></directOrIndirectOwnership><natureOfOwnership><value>By spouse</value></natureOfOwnership></ownershipNature></nonDerivativeHolding></nonDerivativeTable><footnotes><footnote id="F1">Includes shares acquired under MBCN Dividend Reinvestment Plan.</footnote><footnote id="F2">Shares jointly held with spouse and children.</footnote></footnotes><remarks></remarks><ownerSignature><signatureName>Donald E. Villers</signatureName><signature
Date>2003-10-03</signatureDate></ownerSignature></ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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