Abstract: TiO₂ thin films were prepared by sol-gel method. The effects of different thic kness, poro-sity, heat-treated temperature and doping on the hydrophilicity of TiO₂ thin films were investigated. The results show that when TiO₂ film is thinner than 87.2nm,the contact angle decreases with the thickening of the film; when TiO₂ film is thicker than 87.2nm, the contact angle is stable. The increasing of porosity and doping SnO₂ in the film can improve the hydrophilicity. The hydrophilicity will be the best when heat-treated at the temperature of 450~662℃.