Catalytic activity and reaction selectivity of plitinum- and nickel-doped magnesium oxide (Pt/MgO, Ni/MgO) prepared by a wet method have been investigated for steam reforming of ethanol (EtOH) in connection with fuel cell systems. A fixed-bed flow type tubular reactor was used for the catalytic reaction at the temperature range of 250 approximately 500-degrees-C (523 approximately 773 K). The steam reforming of ethanol on Pt/MgO yielded CH4, CO2 and CH3CHO as well as main products, H-2 and CO. The effect of Pt loading on the catalytic activity became samll for the catalysts with higher Pt contents (>ca. 2 wt%), especially at lower reaction temperature (less-than-or-equal-to 350-degrees-C). A maximum H-2 evolution rate was observed when the H2O/EtOH molar ratio in the feed was unity. The reaction on Ni/MgO gave higher selectivity for H-2 and CO formation, but the total catalytic activity of Ni/MgO was lower than that of Pt/MgO. The activity loss was caused by deposition of carbon on Ni/MgO during the initial period of the reaction. The formation of CH4 was slightly suppressed by using a mixture of Pt/MgO and Ni/MgO.