Coprecipitated Au/Fe2O3 catalysts used for low-temperature catalytic oxidation of carbon monoxide have been studied by FT-IR spectroscopy of adsorbed CO. The FT-IR results have shown that after preparation and exposure to a CO/O-2 mixture gold is present on the surface mainly as Au1+ and Au-0 species. It has been found that in the CO oxidation Au1+ is more active and less stable than Au-0.