Abstract: Allyl and aryl groups with weak coordination effect have great influences on the catalytic behavior of metallocene. In order to investigate the catalytic behavior of metallocene in the presence of both allyl and aryl groups, the Group IV metal complexes with allyl and aryl groups on cyclopentadienyl ligands(Cp) were synthesized and characterized with ¹H-NMR, ¹³C-NMR, MS and EA. When combined with methylaluminoxane (MAO), the bifunctional metallocene complexes indicated relativelyhigh catalytic activity for ethylene polymerization and ethylene copolymerization with 1-hexene. When T = 50 ℃, p = 1.0 MPa, the catalytic activity for ethylene polyerization reaches 520 kg/(mol·h). The polymerization results showed that the steric effect of substituent group on Cp ring has great influence on the behavior of catalyst, while the (BifunctionalCp)₂MCl₂ displayed very low activity. However, the mixed CpMCl₂ showed moderate activity under same condition. It is worth to note that compared to mono functional group, the introduction of both allyl and aryl groups not only enhances the copolymerization ability (inserting yield of 1-hexene reaches 4.30%), but also makes the catalyst keeping moderate activity at higher polymerization temperature (Activity reached 156 kg/(mol·h) at 100 °C), which is called as bifunctional effect. The effects of polymerization reaction factors such as temperature, mole ratio of Al/metal and the concentration of catalyst on polymerization reaction have been investigated. It is found that upon incrasing temperature the catalytic activity increased first and then decreased. The activity reached 352 kg/(mol·h) when polymerization temperature is 80 ℃. In fact, the catalytic activity of bifunctional metallocene increased continually as the ratio of n_Al/n_Ti increased, but the polymer molecular weight decreased continually at the same time. However, the catalytic activity decreased as the concentration of catalyst increased, while the polymer’s molecular weight increased first and then decreased.