A new nitrogen-doped carbon support for Pt-based electrocatalysts was prepared by carbonizing polypyrrole formed on the surface of WO3 nanoparticles (WO3-CNx). Morphologies of WO3-CNx and PtSn/WO3-CNx were investigated by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. PtSn nanoparticles were well-dispersed on the surface of WO3-CNx. Electrocatalytic results showed that PtSn/WO3-CNx is more active than PtSn/C in the ethanol oxidation reaction (EOR), since smaller PtSn nanoparticles were grown on the surface of WO3-CNx and highly electrically conductive WO3-CNx facilitated the electron transport occurred during the EOR. PtSn/WO3-CNx also exhibited better durability and higher stability in ethanol oxidation reaction than PtSn/C. These results indicated that WO3-CNx has potential to be used as a catalytic support with high-performance for Pt-based electrocatalysts used in fuel cells. (C) 2014 The Electrochemical Society. All rights reserved.