Abstract: The nano-sized Ni/Y2O3 catalyst prepared by impregnation-hot decomposition-hydrogen reduction(IHDHR) method and impregnation-hot decomposition (IHD) method was studied. The structural characteristics of the catalysts were carried out through X-ray Photoelectron Spectroscopy(XPS), X-ray diffraction(XRD) and BET area. The catalysis- properties of the catalysts were tested using a fix bed reactor fitted in a programmable oven. The Ni/Y2O3 catalyst reduced by hydrogen exhibited high activity for ethanol steam reforming with the conversion of ethanol of 95.3% and the selectivity of hydrogen of 53.6% at 320 ℃, with ethanol conversion of 81.9% and hydrogen selectivity of 43.1% at 250 ℃. The ethanol conversion and hydrogen selectivity were kept about 93% and 53.2% respectively after 60 h stability test at 320 ℃. The test results show that the catalyst reduced by hydrogen has higher activity for ethanol steam reforming at low temperature.