Developing anode catalysts of substantially enhanced activity for hydrogen oxidation reaction (HOR) and anti-CO poisoning performance is of great importance for the application of proton exchange membrane fuel cells (PEMFCs).Herein,we report Pd cluster in situ decorated urchin-like W18O49 (WO2.72) electrocatalysts by a photo-reduction method for high performance HOR.The synthesized Pd-WO2.72-L composite of low loading amount of 0.44 wt.％ Pd by Xenon light reduction exhibits markedly high HOR catalytic activity and stability in 0.5 M H2SO4,and the specific HOR current density and mass activity of Pd-WO2.72-L are ～ 1.5 and～ 80 times those of 20 wt.％ Pt/C catalyst,respectively.Moreover,excellent anti-CO poisoning ability has also been obtained.The excellent HOR activity and anti-CO poisoning performance of Pd-WO2.72-L have been discussed mainly in terms of the dual synergetic catalytic effects between Pd and WO2.72:Pd activation to Pdδ+ by the electron transfer from Pd to W promotes the hydrogen adsorption and activation to H* species,which results in largely elevated HOR activity;Pd degradation due to the CO poisoning is effectively prevented by WO2.72,which is responsible for the excellent CO-tolerance performance.