A novel method has been developed to synthesize anatase nano-photocatalyst of copper phthalocyanine tetrasulfonate (CuPcTs) in hydrothermal condition. When TiO 2 was synthesized by an in situ synchronous process, the surface of TiO 2 particles adsorbed sensitizers. The photocatalyst was characterized by XRD, TEM and UV–vis spectrophotometer techniques. It was found that TiO 2 powder could be sensitized to have wavelength beyond its intrinsic sensitivity using phthalocyanine. Its efficiency was tested with methyl orange (MO) under visible light by UV–vis spectrophotometer. All the photodegradations of MO must experience a dye-sensitized TiO 2 photocatalytic mechanism.