The selective CO oxidation in the presence of excess hydrogen and the complete CO oxidation in the absence of hydrogen were studied over Fe oxide-promoted Pt/γ-Al2O3 catalyst. Various factors in the preparation of catalysts such as the molar ratio of Fe/Pt. the sequence of impregnation. calcinations temperatures and reduction temperatures were examined. XRD, CO chemisorption, TPR, and TPO were conducted to characterize active catalysts. The catalytic activity for CO oxidation was enhanced at low temperatures over Fe oxide-promoted Pt/γ-Al2O3 catalyst compared with Pt/γ-Al2O3 catalyst. The positive effect of water vapor on CO oxidation was also observed. The gradual decrease in the catalytic activity with a reaction time was observed at low temperatures, which is caused by the partial oxidation of Fe oxide.