Pd/WO3 composite film on indium tin oxide (ITO) glass was prepared by electroplating in a solution of 50 mM tungsten-peroxo complex +5 wt.% SDS with 5 mM PdCl2 at room temperature. The structure and composition of the synthesized Pd/WO3 composites were characterized by scanning electron microscopy combined with energy dispersion spectroscopy, X-ray photoelectron spectroscopy and X-ray diffraction. The promotional effect of WO3 for the electrocatalytic activity for hydrazine oxidation was investigated. The peak current of Pd/WO3 ITO glass electrode reached up to 106 mu A, which was 1.7 times as high as that of a Pd-ITO glass electrode (62 mu A) under the same working conditions. It might be mainly attributed to the good dispersion of palladium nanoparticles on WO3 supports. (C) 2007 Elsevier B.V. All rights reserved.