Abstract: Using L-lactide(LLA),glycolide(GA) and 1,3-trimethylene carbonate(TMC) as raw materials and stannous octoate as catalyst,binary copolymers LLA-TMC(PLT) and terpolymers LLA-TMC-GA(PLTG) were prepared by ring-opening polymerization.The copolymers were characterized by ¹H-NMR,FT-IR,GPC,DSC and blood compatibility test to characterize the effect of copolymer composition on the properties such as the crystallization ability,thermal and mechanical properties.Results show that the number-average molecular weights of all copolymers are above 8×10⁴,and the polydispersity index is below 2.0.Compared with PLLA,the introduction of TMC and GA components led to decrease of the crystallization ability,glass transition temperature and tensile strength.The ultimate tensile strength of PLTG is 22.3 MPa with elongation at break of 168.7%.Moreover,the copolymers exhibit good hemocompatibility.