The macroligand effect of the catalytic system WCl6-Et2AlCl for ring opening metathesis polymerization (ROMP) of dicyclopentadiene (DCPD) was investigated. The experimental results show that macroligand effect varies with the structure of the ligands. The macroligands bearing benzene group and steric hindered phenolic unit not only can obviously increase the yield of synthesized polydicyclopentadiene (PDCPD) but also improve the synthesized polymer's mechanical properties. The mechanism of macroligand effect is discussed. The synthesized PDCPD was characterized by methods of scanning electron microscopy (SEM) and X-ray diffraction.