The NiO-MgO solid solution cordierite monolith catalyst was prepared by impregnation. 60 h steam reforming tests were carried out at 1023 K TC was used to analyze the carbon deposition on the catalyst. GC and GC-MS were used to analyze the component of biomass fuel gas and tar. The results show that steam reforming can effectively improve the quality of fuel gas, H-2/CO ratio can be adjusted by steam reforming, The addition of steam can also increase the activity and stability of the catalyst dramatically. The CH4 conversion reached 94%. TG shows that the addition of steam can decrease the carbon deposition on the catalyst. GC-MS result shows that most of the tar was converted to H-2, CO and trace lighter component. Steam reforming can eliminate the biomass tar species more deeply than dry reforming. (C) 2009 Elsevier Ltd. All rights reserved.