Abstract: A series of biodegradable poly(butylene succinate-co-1,2-propylene succinate)s [P(BS-co-PS)] were synthesized by solution polycondensation combined with melt polycondensation from succinic acid with 1,4-butanediol and 1,2-propanediol. The chemical structures of the products were characterized by1H NMR. The characters of the polymers，such as relative molecular weight，molecular weight distribution，crystallinity，thermal properties and mechanical properties，were characterized. P(BS-co-PS) copolymers with molecular weight (Mn) higher than 60000 and molecular weight distribution less than 2.0 were obtained in a reaction time of 4h. With the increase of 1,2-propanediol content，the copolymer has a decrease in crystallinity and Tm and an increase in elongation at break. When the molar content of 1,2-propanediol is 30%，the polymer has an elongation at break as high as 417%. The decomposition temperature of the obtained copolymers is all above 300 ℃.