A series of controlled-release composites of polycapolactone (PCL)/aspirin(ASA) were fabricated via chemically induced phase separation technique with polycapolactone as carrier. The effect of different content of ASA on the morphology, biological activity, hydrophilic performance, porosity and controlled-release performance of the composites were investigated. Results show that the addition of the ASA played a crucial role for forming the unique nanofibrous structure of PCL/ASA composite. The nanofibrous structure of composite fades away with the increasing amount of ASA. The hydrophilic performance increases from 38.00% to 59.34% and the porosity decreases from 96.67% to 52.28% with the increasing ASA-content. Furthermore, both of the pure PCL and PCL/ASA composite all present good biological activity, in other word, both of the nanofibrous structure and ASA all exhibit effect on the biological activity of composite materials. The controlled release of the ASA relates to the structure of PCL/ASA composite, and the accumulated release amount of the PCL/ASA composite with micro- and nano-structure can reach to 25.23% over an equal period of time.