polycaprolactone/poly(ethylene oxide) polylactide tricomponent copolymer (PCEL) with different compositions were synthesized by copolymerization of caprolactone and L-lactide in the presence of poly(ethylene glycol) using stannous octoate as a catalyst. The copolymers were purified and characterized by various analytical techniques such as GPC, FT-IR. 1H NMR, 13C NMR, DSC and X-ray diffractometry. It was evidenced that these copolymers were pure tri-component compounds with exhibited partially random chain structure, and possessd good mechanical properties and variable biodegradqation.