Fluorocarbon groups were introduced onto surfaces of SiO2-covered TiO2 particles (SiO2-TiO2). Oxidation of pentafuluorobenzaldehyde on the surface modified TiO2 powders proceeded much efficiently than that on SiO2-covered TiO2 particles without surface modification. In addition, no enhancement of activity level of surface-modified SiO2-TiO2 for oxidation of benzaldehyde was observed. The enhancement of the surface-modified SiO2-TiO2 is due to the interaction of F atoms between the substrate and fluorocarbon groups introduced on SiO2-TiO2.