Tin-doped indium oxide (ITO) thin films were deposited on glass substrates by direct current (DC) magnetron sputtering,using an ITO target with a combination of 90％ In2O3 and 10% SnO2 in mass fraction. The effects of substrate temperature on the thin film’s transparency and resistivity were studied by spectrophotometer and four-point probe meter. The structural was analyzed by X-ray diffraction (XRD) diffractometer. The interplanar spacing and crystal grain size were calculated, the mechenical properties of films were studied.The results showed that the lowest resistivity could be got while the transparency maintained above 85% with the proper substrate temperature of 200 ℃ , that is to say there is an optimal substrate temperature to prepare the best performance thin film. It showed that the higher the substrate temperature became the better the crystallization was.