Nanoapatite crystals were prepared under different conditions,and the structure and properties of the nanoapatite crystals were investigated.The results indicate that the nanoapatite crystals have a similarity in composition,crystal structure,morphology and cryatallinity to that of bone apatite crystals,and containing CO2-3,Na+,HPO2-4 ets.The nanoapatite grows with the increasing of the hydrothermally treated temperature and the reaction activity.The nanoapatite crystals are rodlike under pressure and needlelike under normal pressure.Such a nanoapatite can be used to make apatite crystals/polymer biomimetic tissue repairing materials and as scaffold for tissue engineering.