Catalytic activity of a 1 wt% Au/TiO2 catalyst is markedly improved by loading a large amount of FeOx, on which the oxidation of CO in excess H-2 is selectively promoted at temperature lower than 60 degrees C. Oxidation of CO with O-2 on the FeOx/Au/TiO2 catalyst is markedly enhanced by H-2, and H2O moisture also enhances the oxidation of CO but its effect is not so large as the promotion by H-2. We deduced that activation of Au/TiO2 catalyst by loading FeOx is not caused by the size effect of Au particles but a new reaction path via hydroxyl carbonyl intermediate is responsible for the superior activity of the FeOx/Au/TiO2 catalyst.