Abstract: A catalyst support of mesoporous MgO was prepared using hydrothermal method, with which a mesoporous Ni/MgO catalyst was prepared by impregnation method. The hydrogen production experiment by steam reforming of biomass oil models and two kinds of commercial biomass oils over the mesoporous Ni/MgO catalyst was conducted. The results show that the furfural conversion, hydrogen yield and hydrogen selectivity increase with increasing the reaction temperature. When the reaction temperature is increased to 600 ℃, the furfural conversion and the hydrogen yield reach 94.9% and 83.2%, respectively. In addition, the hydrogen yields for steam reforming of furfural/acetic acid and furfural/hydroxyacetone reach 87.3% and 86.8%, respectively, which are higher than the corresponding hydrogen yields in steam reforming furfural. The result indicates that the acetic acid or hydroxyacetone can promote the conversion of furfural which is the main organic component in the simulated biomass oil. When the commercial biomass oils is used, the conversion of main organics, hydrogen yield and hydrogen selectivity exhibit an increasing trend with the increase of the ratio of water to the carbon of reactant (S/C = 5, 10, 15, 20, 25). Under the S/C(molar ratio)=20, the conversion of main organic components (furfural, acetic acid, and hydroxyacetone) in two kinds of biomass oils can reach more than 90% and the yield of hydrogen can also be more than 81.0%, showing that the mesoporous Ni/MgO catalyst also has higher catalytic activity for the steam reforming of commercial biomass oils.