TiO2 thin films were prepared with Ti2O3, Ti3O5 and TiO2 as raw materials, by electron-beam evaporation deposition, using O2- ion beam (O2 purity up to 99.99%) as auxiliary means. The crystal structures of the samples were inspected by the X-ray diffraction (XRD) method, and the evaporation character of various raw materials was analyzed. Transmittance spectra were measured through a U-3310 spectrophotometer (wavelength ranging from 200 nm to 900 nm). The refractive index n and the thickness of films were determined from transmission spectra. The experimental results show that the thin films taking Ti2O3 as their raw material have a strong absorption, when taking Ti3O5 and TiO2 as raw materials, the thin films would have good optical properties. The experiments also show that, the crystal structure of all thin films is amorphous before post-annealing and the Ti3O5 is a congruent evaporation phase in the Ti-O system.