Abstract: A terpolymer of α-hexylene/α-octene/α-dodecene was synthesized by bulk polymerization using TiCl4/Al(Et)3 composite catalyst and α-olefin monomers. Effects of polymerization conditions on the intrinsic viscosity of polymer were investigated. The experimental results showed that under the optimum polymerization conditions of using 0.095 g of main catalyst TiCl4 and 0.12 mL of co-catalyst Al(Et)3, V(α-dodecene):V(α-octene):V(α-hexylene) = 4:2:1 (total monomers volume of 40 mL), reaction temperature of -3 ℃ and reaction time of 48 h, the intrinsic viscosity of the synthesized polymer could be up to 15.40 dl/g. The characterization results by FT-IR, XRD and 1HNMR showed that after alcohol washing, the synthesized polymer was free of monomers, and it was the objective α-olefin polymer with low crystallinity to be used as drag reduction agent.