In this study, we prepared rice husk ash-supported nickel catalyst by incipient wetness impregnation in methanation of CO? from H-2/CO2 (4/1) mixture. High selectivity (80-90%) for CH4 formation was found to proceed in the reaction at 623-973 K with the supported nickel. During the investigations of preparation conditions, effects of nickel loading, immersion time, calcination and reaction temperature on catalytic performance were also examined. According to these results, the metal dispersion increases with a decreasing nickel loading. The conversion of CO2 and the yield of CH4 depend on calcination conditions. In addition, the nickel catalyst activity is independent of immersion time; the CH4 yield achieves a maximum value in CO2 methanation at 773 K. Moreover, rice husk ash is found techniques and the reaction test. (C) 1997 Elsevier Science B.V.