The autoclaved-sol was synthesized using titanyl sulfate and peroxide as starting material. Anatase TiO2 thin films were deposited on glass substrates by dip-coating method from autoclaved-sol. It is found that the as-prepared TiO2 thin films contain not only Ti and O elements, but also a small amount of N and Na elements. The anatase crystals of the TiO2 films connected together to form net-like structure after heated, and the films became uniform and compact with increasing heating temperature. The TiO2 films are transparent and the maximum light transmittance exceed 80% under visible light region. At 300 degrees C, the TiO2 thin films show the highest photocatalytic activity. (c) 2006 Elsevier B.V. All rights reserved.