The nano- TiO2 doped with Nd3+ have been prepared by chemical solution deposition on silicon substrates, followed by cathodic electrochemical process using neodymium nitrate solition as the Nd source. The X-ray diffraction (XRD) pattern revealed that the Nd3 -doped TiO2 thin film has a nano-multi-crystal structure. With the increase of the neodymium content, the surface areas of Nd3 -doped TiO2 thin film is larger and the grain diameter decreases, obviously. The existence of the doped element Nd increases the photocatalytic activity of TiO2, and results in red shift of the absorption limit.The highest photocatalytic activity is achieved with the optimal dosage of neodymiumion at 1.2%.