Steam reforming of woody biomass in a fluidized bed was performed at 773, 873, or 973 K. Nonporous silica sand, porous γ-alumina and iron oxide-impregnated porous γ-alumina (Fe-impregnated alumina) were used as bed materials. The addition of iron oxide to the alumina promoted H 2 production at all the temperatures. Larger amounts of H 2 were produced at higher temperatures. Tar evacuated during steam reforming was captured on the Fe-impregnated alumina, and the captured tar (referred to as coke) was reformed with steam to form H 2 . In addition to the reforming, a redox reaction occurred on the iron oxide: CO produced during steam reforming was consumed to reduce the iron oxide, and the reduced iron oxide came into contact with steam to form H 2 . The redox reaction, rather than reforming of the coke, was the predominant pathway of H 2 formation at higher temperatures.