As a new type of thermoset polymer, polydicyclopentadiene (PDCPD) is valued in industry for its excellent mechanical properties, improved heat resistance, and stable physical and -chemical tolerance. Research on the modification of hydrophilic properties is of importance for the expanding application of the material. Hence, copolymer PDCPD was prepared by copolymerization of dicyclopentadiene (DCPD) with 2-Propenoic acid, 2-methyl-, 2-[ [2,3, 3a, 4, 7,7a-hexahydro-4,7-methano-1H-indenyl] oxy] ethyl ester (DCPEMA) via Ring Open Metathesis Polymerization (ROMP). The research results indicated that DCPEMA copolymerized with DCPD via opening cyclopentene group and olefin double bond. Tensile strength of the copolymer was decreased from 64.3 MPa to 9.2 MPa by introducing DPCEMA. Breaking elongation of the copolymer reached 68.34% when n(DCPD) : n(DCPEMA) = 2 : 1 was applied, however, it dropped with the further increasing of the DPCEMA content. The crosslinking density of the copolymer was evaluated via swelling test. The swelling ratio of copolymer showed similar trends as breaking elongation. Moreover, the surface hydrophilicity of the copolymer could be improved dramatically with the introduction of DPCEMA.