Abstract: Uniform TiO2 films have been prepared on silicon substrates by MOCVD and sol-get processes separately. XRD, FE-SEM and AFM were employed to investigate the characteristics of the TiO2 films, including their crystallinities, microstructures and morphologies. In addition, the aqueous orange II was used to investigate their photo-catalytic degradation properties. Effects of different preparation conditions on their crystallinities and photo-catalytic activities were compared. The results showed that the effect of film preparation temperature on the crystallinities and microstructures is considerable, and the films deposited by MOCVD exhibit a higher efficiency in dye solution degradation than that of the films impregnated by sol-gel.