    <SEC-DOCUMENT>0000860546-18-000009-index.html : 20180208
    <SEC-HEADER>0000860546-18-000009.hdr.sgml : 20180208
    <ACCEPTANCE-DATETIME>20180208164119
    ACCESSION NUMBER:		0000860546-18-000009
    CONFORMED SUBMISSION TYPE:	8-K
    PUBLIC DOCUMENT COUNT:		10
    CONFORMED PERIOD OF REPORT:	20180208
    ITEM INFORMATION:		Results of Operations and Financial Condition
    ITEM INFORMATION:		Financial Statements and Exhibits
    FILED AS OF DATE:		20180208
    DATE AS OF CHANGE:		20180208

    FILER:

    	COMPANY DATA:
    		COMPANY CONFORMED NAME:			CORPORATE OFFICE PROPERTIES TRUST
    		CENTRAL INDEX KEY:			0000860546
    		STANDARD INDUSTRIAL CLASSIFICATION:	REAL ESTATE INVESTMENT TRUSTS [6798]
    		IRS NUMBER:				232947217
    		STATE OF INCORPORATION:			MD
    		FISCAL YEAR END:			1231

    	FILING VALUES:
    		FORM TYPE:		8-K
    		SEC ACT:		1934 Act
    		SEC FILE NUMBER:	001-14023
    		FILM NUMBER:		18586255

    	BUSINESS ADDRESS:
    		STREET 1:		6711 COLUMBIA GATEWAY DRIVE
    		STREET 2:		SUITE 300
    		CITY:			COLUMBIA
    		STATE:			MD
    		ZIP:			21046
    		BUSINESS PHONE:		4432855400

    	MAIL ADDRESS:
    		STREET 1:		6711 COLUMBIA GATEWAY DRIVE
    		STREET 2:		SUITE 300
    		CITY:			COLUMBIA
    		STATE:			MD
    		ZIP:			21046

    	FORMER COMPANY:
    		FORMER CONFORMED NAME:	CORPORATE OFFICE PROPERTIES TRUST INC
    		DATE OF NAME CHANGE:	19980105

    	FORMER COMPANY:
    		FORMER CONFORMED NAME:	ROYALE INVESTMENTS INC
    		DATE OF NAME CHANGE:	19930328

    	FORMER COMPANY:
    		FORMER CONFORMED NAME:	ROYALE REIT INC
    		DATE OF NAME CHANGE:	19600201

    FILER:

    	COMPANY DATA:
    		COMPANY CONFORMED NAME:			Corporate Office Properties, L.P.
    		CENTRAL INDEX KEY:			0001577966
    		STANDARD INDUSTRIAL CLASSIFICATION:	REAL ESTATE INVESTMENT TRUSTS [6798]
    		IRS NUMBER:				232930022
    		STATE OF INCORPORATION:			DE
    		FISCAL YEAR END:			1231

    	FILING VALUES:
    		FORM TYPE:		8-K
    		SEC ACT:		1934 Act
    		SEC FILE NUMBER:	333-189188
    		FILM NUMBER:		18586256

    	BUSINESS ADDRESS:
    		STREET 1:		6711 COLUMBIA GATEWAY DRIVE
    		STREET 2:		SUITE 300
    		CITY:			COLUMBIA
    		STATE:			MD
    		ZIP:			21046
    		BUSINESS PHONE:		443-285-5400

    	MAIL ADDRESS:
    		STREET 1:		6711 COLUMBIA GATEWAY DRIVE
    		STREET 2:		SUITE 300
    		CITY:			COLUMBIA
    		STATE:			MD
    		ZIP:			21046
    </SEC-HEADER>
    <DOCUMENT>
    <TYPE>8-K
    <SEQUENCE>1
    <FILENAME>copt12312017earnings8k.htm
    <DESCRIPTION>8-K
    <TEXT>
    Document 1 - file: copt12312017earnings8k.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-99.1
    <SEQUENCE>2
    <FILENAME>copt12312017ex991.htm
    <DESCRIPTION>EXHIBIT 99.1
    <TEXT>
    Document 2 - file: copt12312017ex991.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>3
    <FILENAME>a2017q4cover.jpg
    <TEXT>
    Document 3 - file: a2017q4cover.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>4
    <FILENAME>chart-258cf2d313255fe4926.jpg
    <TEXT>
    Document 4 - file: chart-258cf2d313255fe4926.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>5
    <FILENAME>chart-770f1f5a63375ce79e5.jpg
    <TEXT>
    Document 5 - file: chart-770f1f5a63375ce79e5.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>6
    <FILENAME>chart-50878eab20075582908.jpg
    <TEXT>
    Document 6 - file: chart-50878eab20075582908.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>7
    <FILENAME>chart-209854b78a0c5a79af9.jpg
    <TEXT>
    Document 7 - file: chart-209854b78a0c5a79af9.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>8
    <FILENAME>chart-b62e99a002725b828fe.jpg
    <TEXT>
    Document 8 - file: chart-b62e99a002725b828fe.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>9
    <FILENAME>logo2dtd021015a01a06.jpg
    <TEXT>
    Document 9 - file: logo2dtd021015a01a06.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>10
    <FILENAME>tableofcontentsfinala02.jpg
    <TEXT>
    Document 10 - file: tableofcontentsfinala02.jpg

    </DOCUMENT>
    </SEC-DOCUMENT>