The bioactivity of HA has been tested by its osteoconduction ability in vivo. Nano HA has higher specific surface area and was presumed to have high bioactivity. In this paper, nano needle HA was synthesized by the microemulsion method. The properties of such nano materials were analyzed by the XRD and TEM. The impact of the nano HA on the expression of two hBMSCs’ genes, inhibitor differentiation 2 and ostopontin, and the ALP activity was researched in this paper.