Abstract: The in vitro bioactivity of nano-hydroxyapatite/polycarbonate (n-HA/PC) composite was studied in SBF (simulated body fluid) . The sample surface was characterized by FTIR , XRD and SEM. The results show that n-HA/ PC composite is chemically active in SBF , and the Ca and P ions of carbonated-apatite (CHA) deposit on the surface during soaking in SBF. The Ca-P precipitate on the surface of n-HA/PC composite was CHA. The layer of deposited CHA increases with time , and the morphology of CHA crystal gradually forms. By MTT and SEM analyses , the results show that n-HA/PC composite is not cell toxic and has a good biocompatibility to MG-63 cells.Therefore , this kind of composite could be one of the best potential bioactive materials for the load bearing bone substitute.