The effect of fluidized bed reactor in autothermal CO2 reforming of methane over NiO-MgO solid solution catalysts was investigated by comparing with fixed bed reactor. Methane conversion to syngas was drastically enhanced by using a fluidized bed reactor. The catalyst was reduced and oxidized repeatedly in fluidized bed reactor during the reaction. The enhancement of methane conversion is related to the catalyst reducibility. (C) 2000 Elsevier Science B.V. All rights reserved.