Abstract: MgO-supported nickel catalysts were prepared by impregnation and hydrothermal coprecipitation methods; they were characterized by XRD, N₂ sorption, H₂-TPR, TEM and TG and used in the steam reforming of biomass oil model compound-phenol for hydrogen production. The results indicated that the NiO/MgO solid solution prepared by the impregnation method displays higher surface area (60.6 m²/g) and larger pore diameter (10.1 nm), in comparison with that prepared by hydrothermal coprecipitation. After reduction, the mesoporous Ni/MgO catalyst obtained from impregnation exhibits small and uniform Ni nanoparticles (5.0-6.0 nm) with high dispersion (19.44%). As high surface area is favorable for the dispersion of Ni nanoparticles and mesoporous structure can promote the mass transfer of reactants and products, the Ni/MgO catalyst exhibits high activity as well as excellent coke resistance ability and long-term stability in the steam reforming of phenol.