A comparative study on Au/TiO2 catalysts prepared by impregnation with HAuCl4 of commercial TiO2 or by impregnation of sol-gel derived TiO2 has been carried out during CO oxidation. Specific surface areas and mean Au particle of 49 and 74 m(2)/g and 35 and 25 Angstrom were obtained for impregnated commercial TiO2 and sol-gel preparations respectively. XRD patterns shown that in sol-gel derived TiO2 only anatase phase was identified, while in commercial TiO2 anatase and rutile phases co-exist. Titania support effect on Au activity for the oxidation of CO has been observed. The light-off during the reaction on Au/TiO2 initiates at 50degreesC, whereas for commercial impregnated TiO2 catalyst the light-off initiates at 200degreesC.