Objective To prepare cisplatin-loaded polycaprolactone microspheres and investigate the influencing factors on drug-loading rate, particle size and sustained release property. Methods The microspheres were fabricated by oil-in-water(O/W)emulsion and solvent evaporation technique. The drug loading rate and encapsulation efficiency of microspheres were investigated by using ultraviolet spectro-photometry(UV)and the shape and particles size of microspheres were characterized by polarizing microscope and scan electron microscope(SEM). Results The results showed that cisplatin-loaded microspheres of 54 μm size were prepared with high molecular weight of polycaprolactone when the concentration of polyvinyl alcohol was 3.5% and the speed of emulsification was 800 r/min. The drug loading rate could reach 7.8% and the encapsulation efficiency of cisplatin could reach about 75%. The drug release behavior of microspheres was related to the size of microspheres and fitted well with the Fickian diffusion model. Conclusion The resulting cisplatin-loaded microspheres has good shape, homogeneous particle size and good sustained release properties under the optimized conditions.