Here, different silica materials such as fumed SiO2 (f-SiO2), porous granular SiO2 (p-SiO2) and mesoporous SBA-15, were used to prepare supported Pt catalysts by simple impregnation method. And their catalytic activities were investigated for the complete oxidation of HCHO. The physicochemical properties of the Pt/SiO2 catalysts were characterized in order to understand the role of supports and the nature of active centers.