Abstract: As the bioceramic material itself，hydroxyapatite(HA)has deficiency in intensity and toughness.The purpose of adding zirconia into HA is to enhance its intensity and toughness without impact on its bioactivity.Firstly，the influence of pH and hydrothermal time on crystallization of HA was studied and a better hydrothermal condition was obtained.Secondly，Ca↑2+ and PO↑3-↓4 were added on the fine particles of ZrO↓2·xH↓2O respectively and control the pH values at the same time to make HA deposit on the surface of ZrO↓2·xH↓2O to prepare colloidal particles with coating structure.And then the coating colloidal fluid was treated under the above said hydrothermal condition.Results indicated that HA and zirconia can affect crystallization rate of each other greatly；zirconia is quite difficult to crystallize when it is coated by HA；and proved the coating structure is close and tight.