The photocatalytic properties of TiO 2 can be used in treatment of pollutions. Considering to relatively high band gap of TiO 2 (3/2 eV), this material is active in the UV radiation. For activation of this photocatalyst in the visible area and efficient use of sunlight, its band gap should be reduced. Several studies have shown to achieve this objective, some compounds can be doped. In this project, TiO 2 -WO 3 composite nanotubes were prepared by in-situ anodizing method. The morphology, structure and optical properties of these nanotubes were charactrized by SEM, XRD, EDAX and UV-Visible. These studies confirmed the formation of nanotubes, presence of tungsten and decrease in the band gap of the TiO 2 of these compounds compared to TiO2. Photocatalytic properties of these nanotubes in the degradation of methylene blue dye showed that by doping of tungsten, their photocatalytic properties were improved compared TiO 2 . In other words, large amounts of methylene blue were degraded. At different concentration of tungsten, due to better respond to the mentioned tests; 0/012 M was selected as optimized sample. In this project, some metals such as gold, platinum, palladium and cobalt, each of in certain concentrations and time were doped in TiO 2 nanotubes and TiO 2 -WO 3 by photo-assisted deposition method. Morphology, structure and optical properties of these nanotubes were characterized by SEM, XRD, EDAX and UV-Visible. Redults shown that thses metals are present on the surface of the nanotubes and the band gap has been reduced. Their photocatalytic properties for the degradation of methylen blue dye were studied. Results showed that by metal doping, photocatalytic properties were improved and stability is desirable. In the platinum doped sample, Pt/TiO 2 -WO 3 at 180 minutes due to better respond to the tests listed and degradation of more color was chosen as the optimized sample. For samples doped with gold, the sample Au/TiO 2 -WO 3 sample was optimized at 60 minutes. In the case of Pd, Pd/TiO 2 -WO 3 sample at 60 minutes, for example, and neither the optimized choice as well as a sample of cobalt Co/TiO 2 -WO 3 at 60 min was selected as optimized sample.