Random copolymers of trimethylene carbonate (TMC) and e-caprolactone (CL) have been synthesized by ring-opening polymerization of TMC and CL in the presence of stannous octoate. The effects of feeding dose, reaction temperature and polymerization time, and effect of catalyst content on the copolymerization were investigated. The results showed that the composition of the copolymers was in good agreement with the feeding dose, and the molecular weight of the copolymers decreased firstly with increasing CL content and then increased. The decrease in the reaction temperature, polymerization time and catalyst content would increase the molecular weight of the copolymers. Furthermore, the feeding dose affected the thermal and mechanical properties of the copolymer largely, and the possessing different properties of random copolymers could be obtained by adjusting the copolymer compositions. This work could optimize the polymerization conditions to achieve the copolymers with controlled properties for implant applications. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012