In this paper, a simple one-pot thermal decomposition method was successfully used to synthesize a novel Cs3PW12O40/WO3 composite for the first time. The synthesized composite was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), FTIR, diffuse reflectance spectroscopy (DRS) and N-2 adsorption-desorption techniques. The photocatalytic activity to degrade RhB molecules over Cs3PW12O40/WO3 composite was evaluated under xenon light irradiation. The results indicated the complete degradation of RhB molecules over Cs3PW12O40/WO3 composite after 30 min irradiation. However, the photocatalytic degradation of RhB over WO3 and Cs3PW12O40 after 80 min light irradiation are nearly 52%, and 68%, respectively. The enhanced photocatalytic activity of Cs3PW12O40/WO3 composite compared with WO3, and Cs3PW12O40 was ascribed to the strong interaction between WO3 and Cs3PW12O40, which effectively reduces the recombination of photogenerated electron-hole pairs. Based on experimental results, the possible mechanism of photocatalytic reactions on the Cs3PW12O40/WO3 composite photocatalyst was investigated, and the hydroxyl radical ((OH)-O-center dot) and superoxide radical (O-center dot(2)) were determined as the main active species in the photocatalytic degradation of RhB over Cs3PW12O40/WO3 composite. (C) 2018 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.