Abstract: Pure TiO₂, Cu doped TiO₂, Nd doped TiO₂ and Cu-Nd co-doped TiO₂ were prepared through sol-gel method with tetrabutyl titanate as raw material. The samples were characterized by means of X-ray diffraction, Fourier transform infrared spectrometer. The photocatalytic performance of different TiO₂ particles and the effect of amount of Cu, Nd were studied using ultraviolet lamp of 15W as the illumination device and unsymmetrical dimethyl-hydrazine as the stimulant pollutant. The results indicate that doping has changed the parameters of lattice, improved the photocatalytic performance of TiO₂, and the co-doping has showed its synergistic effect. The most efficient degradation was found for co-doped TiO₂ particles under the conditions of x_Cu=2.0%, x_Nd=1.5%. When the reaction temperature is 25 ℃, the degradation rate of unsymmetrical dimethylhydrazine could reach 93.4% by catalysis of 0.6g/L in 60 minutes.