Addition of Pd to Ni0.2Mg0.8Al2O4 promoted oxidative steam reforming of methane, and it gave high activity under high partial pressure of steam and low W/F, where Ni0.2Mg0.8Al2O4 showed very low activity. The Ni0.2Mg0.8Al2O4 requires the H-2 reduction pretreatment; however, Pd/Ni0.2Mg0.8Al2O4 can be activated automatically by the reactant gases of oxidative reforming of methane.