〔Abstract〕 Objective To evaluate the physicochemical properties of hydroxyapatite(HA)/gelatin porous scaffold and its effect on the proliferation and differentiation of rat bone mesenchymal stem cells(rBMSC). Methods HA/gelatin scaffold was fabricated by using coprecipitation method with different cycle times. And evaluated the structural/chemical characterization of the scaffolds. Cellular proliferation of rBMSC seeded on the scaffolds were examined by scanning electron microscopy(SEM), live/dead staining and CCK8, respectively. The osteogenic differentiation of rBMSC was analyzed by alkaline phosphatase(ALP) staining analysis. Results SEM showed that the surface of the composite scaffold was precipitated with rod-shaped particles and X-ray diffraction(XRD) showed that the precipitate was hydroxyapatite. Compared to 2 HA, 3 HA and gelatin groups, SEM showed that rBMSC adhered and stretched well on the 1 HA and the results of CCK8 showed that the viability and proliferation of rBMSC was enhanced in 1 HA. rBMSC seeded on 1 HA induced the ALP expression which was analyzed by ALP staining analysis, and the difference was statistically significant(P<0.05). Conclusion The fabricated 1 HA/gelatin scaffold has an excellent biocompatibility and it promotes the proliferation and differentiation of rBMSC. These results provide a promising scaffold for bone tissue engineering.