Indium tin oxide (ITO) films have been widely used as transparent conductive electrodes for optoelectronic devices. Its light transmittance, electrical conductivity, surface roughness, work functions matching with substrates and carrier transferring performance at the interface all affect the performance of optoelectronic devices. In this paper, ITO films were prepared by RF magnetron sputtering. Influences of substrate heating temperature on properties of ITO films were systematically studied. The Sn doped indium oxide ceramic target was used, the composition molar is m(In2O3)∶m(SnO2)=90∶10. The prepared films were characterized by XRD and SEM, and effects of different substrate temperatures on the crystallization and morphology properties of ITO films were studied respectively. The effects of substrate temperature on the photoelectric properties, carrier concentration, work function and carrier transferring properties of ITO films were studied by UV-Vis spectrophotometer, Hall effect tester, ultraviolet photoelectron spectrometer (UPS) and current-voltage curve, respectively. It is found that the comprehensive properties of the ITO film are the best when the substrate temperature is located at 200 ℃. At this time, the ITO film has good crystallinity, smooth surface, average transmittance over 80% in visible light band, excellent conductivity and current transmission characteristics, and the composition of the film is consistent with that of the target.