The electrocrystallization hydrothermal synthesis process was used for fabricating hydroxyapatite biocoatings on metallic substrates at low temperatures with aqueous electrolytes containing Ca and P bearing ions. Scanning electron microscopy (SEM) , X ray diffraction (XRD) and infrared spectroscopy (IR) were used to analyze the morphology, structure and chemical composition of the coatings. Bonding strength and biocompatibility of the coatings were measured. The results show that the coatings prepared by this process are wholly composed of needle like hydroxyapatite, and hvae a good uniformity and high purity. The bonding strength is about 15 MPa. Though the mass of the coating decreases as the coating is immersed in the Ringer's solution for 12 months, no changes in the phase composition and morphology were observed.