Abstract: The chemical composition, crystal structure pre-reduction, and post - reduction density and the important characteristics such as surface area, pore volume, porosity, mean pore radius and pore distribution of A301 catalyst have been studied systematically. The results show that the catalyst specific area and its pore structure is generated during the reduction process and the catalyst before reduction can be regarded as a compact solid with little pore. The BET surface area and a - Fe crystalline size of the A301 are comparable with the traditional catalyst A110-2. A301 s α- Fe and alkali surface area aresmaller than A110 - 2, but its acid surface area is larger than A110-2. Its bulk density and particle density are larger than A110 - 2 too, but its true density is not. The pore volume, porosity and pore radius of A301 are smaller than the traditional catalyst. This is inconsistent with the results reported by Nielsen A. The increase of activity of the Fe1-x O based A301 catalyst is due to the change of the surface properties ( such as enlargement of the acid surface area ) and surface structure of the α- Fe reduced fromFe1-x O, rather than the enlargement of the BET specific area , pore radius or increase of Fe content .