The hydroxyapatite, (Ca-10(PO4)(6)(OH)(2)), HAp, film was deposited on a titanium substrate in aqueous solutions by controlling the substrate temperature and its surface ion concentrations. The HAp can be directly coated only on the substrate quickly by heating up the substrate due to passing an alternating current through a substrate in the aqueous solution (thermal substrate method). The morphology of HAp crystals formed on Ti substrate depended on solution pH, surface temperature, ion concentration, surface roughness of substrate and heating time. On the other hand, electrochemical reaction gives a supersaturation state on the electrode. Electrodeposition has been a newly developed method as a high-speed deposition. The supersaturation state of OH- ions can be generated just in the vicinity of metal substrates and the heterogeneous nucleation is promoted on them. The effect of H2O2 on coating characteristics was examined to obtain biomineral films. H2O2 addition in electrolytes enhanced the formation of OH- ions at the solution/electrode interface at a lower cathodic overpotential. It increased nucleation density and improved adhesion of deposits on titanium substrates. The HAp formation process was clarified from mass changes using electrochemical quartz crystal microbalance technique.