A few FeOx following a thermal-treatment at different temperatures supported Pt catalysts (Pt/FeOx-T) were prepared by a facile colloid deposition method, and their catalytic properties were investigated in the oxidation of formaldehyde at ambient temperature. These catalysts were characterized by XRD, BET, H2-TPR, FTIR and TEM. The results showed the thermal treatment temperature could affect the BET surface area, oxidation-reduction property of FeOx, the amount of surface hydroxyls of Pt/FeOx and a strong interaction was observed between Pt species and FeOx. The activity test indicated that the optimal catalytic performance was obtained over 1.5wt% Pt/FeOx-100 showed the best catalytic performance, under the conditions of 25?C, the relative humidity of 55%, a gaseous hourly space velocity of 60 000 cm3g-1h-1, and the HCHO conversion was 96.2%.