Indium-Tin-Oxide (ITO) thin films were deposited on glass substrates using DC magnetron reactive sputtering at different bias voltages and substrate temperatures. Some improvements were obtained on film properties, microstructure and other physical characteristics for different conditions. Amorphous and polycrystalline films can be obtained for various deposition conditions. The transmission, absorption, spectral and diffuse reflection of ITO films were measured in some ranges of UV-Vis-NIR. The refractive index (n), Energy band gap E-g and the surface roughness of the film were derived from the measured spectra data. The carrier density (n(c)) and the carrier mobility (mu) of the film micro conductive properties were discussed. The films exhibited suitable optical transmittance and conductivity for electrochromic applications.