Abstract: Nano-sized hydroxyapatite powder is prepared by means of hydrothermal synthesis with CaCl₂ and H₃PO₄ as precursores under the conditions of 150℃, pH 9~10 for 4 hours.The prepared particles are characterized by virtue of Fourier Transform Infrared (FT-IR) spectroscopy, X-ray diffraction (XRD) , transmission electron microscopy (TEM) .The result indicates that the prepared particles have a size 60~100 nm in c axis and 20~30 nm in a axis, which is similar to that in human bone.Polyetheretherketone-hydroxyapatite (PEEK-HA) composite is prepared by injection molding.Mechanical property examination results of the composite indicate that a proper addition of HA and annealing treatment may improve the mechanical properties of the composite.