Abstract: SnO₂ films prepared by two-step thermal oxidization method.Tin films deposited by evaporation,were oxidized in oxygen flow below the melt-pointing temperature of metal tin for 30mins,and then,increased oxidization temperature to 400,450,500,and 550℃ for 2h respectively.The effects of oxidation temperature on the structural properties,optical properties of the samples were investigated by X-ray diffraction（XRD）,scanning electron microscopy（SEM）,and UV-VIS transmittance spectra.XRD analyses revealed that various diffraction peaks of SnO₂ were observed even with the oxidization temperature of 400℃.When Tin films were oxidized at a temperature of 550℃,various diffraction peaks were indexed as（110）,（101）,（200）,and（211）.Moreover,the（200） peak from the SnO₂ is hardly detected,if the oxidation temperature is less than 550℃.The surfaces of SnO₂ thin films were compact and uniform by SEM measurements.It was found that the grain size and the surface morphology correlate with the oxidation temperature.UV-VIS transmittance spectra showed the optical transmission of SnO₂ thin films in the visible wavelength region improved with increasing oxidation temperature.And the energy gap increases as the oxidation temperature increases too.The technique developed in this work also has many advantages than other methods for fabricating SnO₂ films,such as easiness in large area fabrication,low-cost,high reliability in control processing.