A novel anodic electrocatalyst Ir0.4Ru0.6MoxOy for solid polymer electrolyte (SPE) water electrolysis is prepared by the modified Adams' fusion method. The XRD, ICP, and BET are employed to determine the physical characteristics of Ir0.4Ru0.6MoxOy and Ir0.4Ru0.6O2, and the electrochemical properties of the electrocatalysts are examined by cyclic voltammetry (CV) in 0.5 M H2SO4. The results show that Ir0.4Ru0.6MoxOy has much smaller particle size, larger specific surface areas and active surface area compared with Ir0.4Ru0.6O2. The results of single cell performance and the electrochemical impedance spectroscopy (EIS) tests also prove that Ir0.4Ru0.6MoxOy has higher performance than Ir0.4Ru0.6O2. (C) 2009 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.