Anatase phase TiO2 and WO3-doped TiO2 thin films were prepared on microscope glass slides by self-assembly method. The films were characterized by atomic force microscope (AFM) and UV-VIS spectrophotometer. The photocatalytic activities of the films were tested on the degradation of rhodamine B dye. The results indicate that when the atom ratio of W/Ti is 2at%, the photocatalytic activity of the TiO2 is improved.