The TiO2 nanomembrane doped by RE ions were prepared by mixing RE ions into TiO2 solution and the photo-catalytic properties of the coating glass with TiO2 membrane doped by RE ions to methylbenzene degradation under ultraviolet were investigated. AFM photoes show that the surface of coating glass with TiO2 nanomembrane doped by Ce3+, Ce4+, Y3+ are composed of particles with diameters of 30～50 nm. The researches on photo-catalytic properties prove that the surface of coating glass with TiO2 nanomembrane doped by RE ions possesses good photocatalytic properties under ultraviolet and the degradation percents of methylbenzene are more than 90% when the degradation time is shorter than 160 min. When the mole ratio of Ce3+, Y3+, Ce4+ to TiO2 is 0.002 the degradation percents of methylbenzene are respectively 92.85%, 91.87% and 91.15% under 254～365 nm ultraviolet in 50 μg·ml-1 methylbenzene solution. The photocatalytic ability of the surface of coating glass with TiO2 nanomembrane doped by Ce3+ under ultraviolet to degrade methylbenzene increases as the concentrations of RE ions increase and their optimum percentage of degradation are 98.50%, 97.50% and 96.35.5% respectively. The higher the concentration of methylbenzene solution the lower the percents of the methylbenzene degradation of the coating glass are, and the bigger the ratio of the areas of coating glass to the volume of methylbenzene solution the higher the degradation effect of methylbenzene is. The TiO2 nanomembrane doped by RE ions were prepared by mixing RE ions into TiO2 solution and the photo-catalytic properties of the coating glass with TiO2 membrane doped by RE ions to methylbenzene degradation under ultraviolet were investigated. AFM photoes show that the surface of coating glass with researches on photo-catalytic properties of that surface of coating glass with TiO2 nanomembrane doped by RE ions possesses good photocatalytic properties under ultraviolet and When the mole fraction of Ce3 +, Y3 +, Ce4 + to TiO2 is 0.002 the degradation percents of methylbenzene are respectively 92.85%, 91.87% and 91.15% under 254 to 365 nm ultraviolet in 50 μg · ml -1 methylbenzene solution. The photocatalytic ability of the surface of coating glass with TiO 2 nanomembrane dope d by Ce3 + under ultraviolet to degrade methylbenzene increases as the concentrations of RE ions increase and their optimum percentage of degradation are 98.50%, 97.50% and 96.35.5% respectively. The higher the concentration of methylbenzene solution the lower the percents of the methylbenzene degradation of the coating glass are, and the bigger the ratio of the areas of coating glass to the volume of methylbenzene solution the higher the degradation effect of methylbenzene is.