Supported metal oxide catalysts, namely Ce/TiO(,2) and V/TiO(,2) were prepared by technique and calcined at 723 and 823 K for catalytic oxidations of toluene in air. The catalysts, characterized by X-ray diffraction (XRD), were mainly TiO(,2) (anatase) phase. The oxidation states of cerium and vanadium on the anatase, investigated by X-ray photoelectron spectroscopy (XPS), were Ce(III) and V(IV) mixed with V(V), respectively. The oxidation reactions of toluene in the presence of Ce/TiO(,2) and V/TiO(,2) were perfo rmed by a fixed bed reactor on line to a Gas chromatograph at 723 K and GHSV 7512 h('-1). The results showed that 3%V/TiO(,2) oxidized toluene up to 100% for the fresh catalysts during 60 min reaction time and 95% for 30 min for the regenerated ones, whereas 3%Ce/TiO(,2) performed almost 90% for 30 min and 20 min reaction time for the fresh and the regenerated catalysts, respectively. The catalysts oxidized much better after the catalyst pretreatments in air at 823 K for 3 h before the reactions. It could be assumed that the active species in the catalytic oxidation were Ce(IV) and V(V). The cerium species on the anatase also showed the oxygen storage property, which oxidized toluene up to 40% for at least 90 min. To study selectivity, 8%Ce/TiO(,2) and 3%V/TiO(,2) were chosen because they have the highest activity. Both of them have selectivity to methanol, benzene and bezaldehyde while vanadia is selective to benzaldehyde formation.