[Objective]To develop a scaffold with three dimension porous structure,composed of nano-hydroxyapatite and gelatin and evaluate its biocompatibility.[Method]Three different kinds of porous scaffolds were prepared by gelatin in combination with 10wt%,20wt%,30wt% nanohydroxyapatite using freeze-drying method.The differences among three kinds of porous scaffolds in porosity,pore size,PH value and mechanical strength were detected.And the optimal scaffold was chosen.MTT test was also done to assess cytotoxicity of the scaffolds.The effects of the scaffolds on BMSCs growth were also detected using co-culture method.The materials was buried in the back muscles of New Zealand rabbits.Histological staining was used to evaluate the biological safety of the scaffolds.[Result]Stereomicroscope and SEM observation showed that the scaffold had three dimension porous structure.As the content of nHA increased,the diameter of the pore,porosity and water absportion of scaffolds decreased,but the strength of anti-compression enhanced.The scaffold composed with 20 wt% nHA was chosen as the optimal.The intrinsic cytotoxicity assessment of scaffolds using MTT test and co-culture method showed that the scaffolds had no cytotoxic effect on BMSCs.HE staining showed that the histocompatibility between scaffolds and surrounding muscle tissue was good and no immune rejection was found.[Conclusion]The prepared gelatin/nHA scaffold has three dimension porous structure,good pore diameter and porosity,non-toxicity and good biocompatibility,which make it a suitable candidate as an alternative carrier for bone tissue engineering.