Ring-opening metathesis polymerization (ROMP) of dicyclopentadiene (DCPD) was conducted by using catalyst systems WCl6-Et2AlCl, (WCl6-PhCOMe)-Et2AlCl and their polystyrene supported counterparts. Experimental results indicate that the acetophenone modified catalyst system shows better catalytic properties than the unmodified system does and that supporting the catalysts on a polystyrene can improve further the catalyst systems'catalytic properties. As a result, the polymer yield of the ROMP increased, the mechanical properties of NIS (notched impact strength), TS (tensile strength) of synthesized polydicyclopentadiene (PDCPD) enhanced. The mechanism in which supporting improves the properties of the catalyst systems is discussed.