The hydroxyl-terminated poly(butylene succinate)oligomer (OH-PBS-OH) was prepared by melt polycondensation using 1,4-butanedioic acid (SA) and 1,4-butanediol (BD) as reactants. By the half-esterification of methoxypoly(ethylene glycol) (MeOPEG) with succinic anhydride, a carboxyl-terminated prepolymer was synthesized, and then by activating the prepolymer using thionyl chloride, a new prepolymer (MeOPEG-COCl) was synthesized in toluene solution. MeOPEG-PBS-PEGOMe block copolymer was synthesizedby solution polymerization of MeOPEG-COCl and OH-PBS-OH as starting materials. The structure, crystallinity and enzymatic degradation properties of the copolymers were characterized by IR, ¹H-NMR, DSC, WAXD and POM, etc.The results show that the incorporation of PEG chain in MeOPEG-PBS-PEGOMe block copolymer could not change the crystal structure, but the crystal morphologyis changed from spherulite to wheat-like crystal. Compared with PBS, the addition of PEG segment decreases thecrystallization rate, and accelerates the degradation rate of the enzyme.