Because poly(L-lactic acid) (PLLA) is a biodegradable polyester with low immunogenicity and good biocompatibility, it is used as a biomaterial. However, hydrophobic PLLA does not have any reactive groups. Thus, its application is limited. To increase the hydrophilicity of PLLA and accelerate its degradation rate, functionalized pendant groups and blocks were introduced through copolymerization with citric acid and poly(ethylene glycol) (PEG), respectively. This article describes the synthesis and characterization Of poly(L-lactic-co-citric acid) (PLCA)-PLIA and PLCA-PEG multiblock copolymers. The results indicated that the hydrolysis rate was enhanced, and the hydrophilicity was improved because of the incorporation of carboxyl groups in PLCA-PLLA. The joining of the PEG block led to improved hydrophilicity of PLCA, and the degradation rate of PLCA-PEG accelerated as compared with that of PLCA-PLLA. (C) 2003 Wiley Periodicals, Inc.