Abstract: The non-uniform lead-doped TiO2 thin films deposited on glass substrates were prepared by the sol-gel method. The surface features of the photo-catalytic composite films were investigated by means of AFM, XRD and UV-Vis. The photo-catalytic activity of the films was then characterized by using the model reaction of the photo-catalytic degradation of methyl orange. The results show that, for the non-uniform lead-doped TiO2 thin film (PbDx) and the uniform lead-doped TiO2 thin film (PbTx), the optimum doping mole ratios of Pb/Ti are all 0.005. It is also shown that the maximum apparent degradation rate constant of PbD0.005, that is, 7.37×10-3 min-1, is 2.52 times that of the pure TiO2 thin film, while that of PbT0.005 is 5. 95×10-3 min-1. The doping mechanism was discussed based on the separation efficiency theory of charge carrier.