Highly transparent conducting indium tin oxide(ITO)films have been prepared on glass substrates by reactively evaporating In-Sn alloy in a system with an oxygen partial pressure of (1-2)×10-4 Torr and a substrate temperature between 100 and 320℃. Mechanically stable polycrystalline conducting ITO films having a preferred orientation with the (111) planes parallel to the substrates were deposited with resistivities in the range from 1.12×10-4 to 3.07×10-4 cm, with carrier densities between 7×1020 and 1.27×1021 cm-3 and Hall mobilities between 27 and 40 cm2 V-1 S-1. The average transmittance reached 95% for a film 175 nm thick in the wavelength range of the visible spectrum. The resistivities and transmittances of the obtained films depended on the oxygen partial pressures and substrate temperatures during film fabrication.