Synthesis methods of hydroxyapatite with different calcium sources under hydrothermal conditions were compared.From SEM,XRD and FT-IR results,it is concluded that the eggshell could be used as an effective source of Ca2+,and its porous structures could also be selected as a hard template in the formation of flower like hydroxyapatite.Sodium dihydrogen phosphate was used as the sources of PO3-4 to corrode the CaCO3 to hydroxyapatite.The result indicated that the sodium phosphocreatine would have a wide application prospect in the synthesis of high purity hydroxyapatite by hydrothermal decomposition.