Three kinds of silica materials, including fumed SiO2, porous granular SiO2and mesoporous SBA-15, wereadopted to prepare supported Pt catalysts by impregnation method. The catalytic properties of these sil-ica supported Pt catalysts (Pt/SiO2) were investigated for the complete oxidation of formaldehyde(HCHO). Among them, fumed SiO2supported Pt catalyst (Pt/f-SiO2) shows very high catalytic activity,which could completely oxidize HCHO even at ambient temperature. According to the results of catalystcharacterization, it was proposed that the nature of silica supports could affect the particle size and thechemical states of platinum species and then further influence the redox property of Pt/SiO2catalysts.Compared with other silica supported Pt catalysts, Pt/f-SiO2catalyst possesses higher ratio of metallicPt species, which might be a key factor in improving its capability to activate molecular oxygen and con-sequently to oxidize HCHO at low temperature.