Novel maleated poly(D,L-lactide-co-glycolide) (MPLGA) was melt copolymerized directly from maleic anhydride, D, L-lactide and glycolide monomers with stannous octoate as catalyst and benzoyl peroxide as initiator. FTIR, H-1 NMR, GPC and maleation content were employed to qualitatively characterize the synthesized MPLGA. The effects of the catalyst dosage, reaction time and reaction temperature on weight average molecular mass, polydispersity index and maleation content of MPLGA were also investigated. The results indicated that the novel MPLGA was successfully obtained using melting-copolymerization method. MPLGA, with a weight average molecular mass of about 5.39 x 10(4) Da, a polydispersity index of 1.51 and a maleation content of 7.1 wt%, was obtained when polymerization was conducted with catalyst dosage of 0.03 wt% for 36 h at 140 degrees C. The results indicated that the introduction of maleic anhydride into PLGA may offer new and important options for biomaterial applications.