Abstract: A series of Pt-FeO_x/γ-Al₂O₃ catalysts were prepared by colloid-deposition method and characterized by XRD, TEM, BET, XPS, H₂-TPR and FT-IR to investigate the effects of calcination temperature on the surface structure of Pt-FeO_x/γ-Al₂O₃ catalyst and its catalytic performance in catalytic HCHO oxidation. The characterization results showed that the applied calcination temperature greatly influenced the redox properties and chemical states of the Pt species, as well as the amount of surface hydroxyl groups. All resultant Pt-FeO_x/γ-Al₂O₃ catalysts demonstrated activity in HCHO oxidation. The sample with calcination at 200 ℃ exhibited the best performance, which afforded 100% conversion of HCHO into CO₂ and H₂O at room temperature. The catalysts with lower calcination temperature should be beneficial to have a better valence distribution of Pt species and produce more accessible interface active sites like Pt-O-Fe species, thus endowing Pt-FeO_x/γ-Al₂O₃ catalyst with relatively high activity for the oxidation of formaldehyde under mild conditions.