The　hydrothermally　treated　bauxite　with　high　surface　area　was　employed　as　the　Pt　based　catalyst　support.　A　series　of　Pt/bauxite　catalysts　were　prepared　by　incipient-wetness　impregnation　method.　The　loading　of　Pt　was　varied　from　0.5wt%　to　2.0wt%.　The　catalysts　were　characterized　by　XRF,　low　temperature　nitrogen　adsorption-desorption,　XRD,　H-2-TPR　and　CO-TPD.　The　catalyst　performance　for　CO　oxidation　reaction　was　also　investigated.　The　results　indicate　that　Pt/bauxite　catalysts　have　excellent　property　for　CO　oxidation　reaction.　Especially　when　the　reaction　temperature　is　at　200　degrees　C,　CO　conversion　rate　of　1.0%Pt/bauxite　is　93.2%,　while　1.0Pt/Al2O3　is　only　9.4%,　attributed　to　the　interaction　between　Pt　and　Fe2O3　in　the　modified　bauxite,　and　the　interaction　could　decrease　the　reducing　temperature　of　Pt　oxide　and　Fe2O3　and　also　improve　the　adsorption-desorption　behavior　of　Pt/bauxite　catalysts　for　CO　molecule,　thus　increasing　the　CO　Oxidation　activity.