The catalyst, Ni nano-particles supported on Y2O3, which was prepared by three methods, was studied. The structural properties of the catalysts were tested through X-ray diffraction and BET area. The catalyst of Ni/Y2O3 exhibits high activity for ethanol steam reforming with conversion of ethanol of 98% and selectivity of hydrogen of 38% at 300degreesC, conversion of ethanol of 98% and selectivity of hydrogen of 55% at 380degreesC. With temperature increasing to and above 500degreesC, the conversion of ethanol increased to 100%, but the selectivity of hydrogen did not increase so much, it was 58% at 600degreesC. The catalyst has long-term stability for steam reforming of ethanol and is a good choice for ethanol processors for fuel cell applications. (C) 2003 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.