Abstract: The phase structure and microstructure of BaTiO₃ films,prepared through microarc oxidation,are analyzed by means of X-ray diffraction(XRD),transmission electron microscope(TEM) and energy dispersive X-ray spectroscopy(EDS).The re-sults showed that the films are mainly composed of primitive tetragonal and primitive hexagonal BaTiO₃and amorphous phase when they were deposed in 0.2 mol/l Ba(OH)₂ solution with current density of 5A/cm² and frequency of 250Hz for 30 minutes.The films are mainly composed of primitive tetragonal BaTiO₃,the amorphous phase disappeared and primitive hexagonal Ba-TiO₃ remained partly,when they were annealed at 1200℃for 8 hours.