Tungsten doped tantalum oxide (W-Ta2O5) particles were synthesized by a low temperature hydrothermal method. The phase structure of W-Ta2O5 particles was characterized by X-ray diffraction (XRD). The XRD results indicated that the samples belonged to orthorhombic crystal. The photocatalytic activity of samples was investigated with degradation methylene blue (MB) under ultraviolet light. The degradation efficiency of MB under the catalysis of W-Ta2O5 particles attained 91% when the reaction time was 7 h. The kinetics of MB degradation was respect to the first-order in the presence of the photocatalysts.