Pt/Ce-ZrO2 catalysts have been designed and applied to selective CO oxidation at low temperature. Both tetragonal and cubic phase Ce-ZrO2 supports were prepared by co-precipitation method to get high surface area materials after calcination at 500degreesC for 6 h in air. Selective CO oxidation was conducted using stoichiometric amounts of O-2. Cubic Ce-ZrO2 supported Pt catalyst exhibited 78% CO conversion and 96% CO2 selectivity even at 60degreesC, while Pt/Al2O3 catalyst showed less than 1% CO conversion at the same condition. The higher CO conversion and CO2 selectivity (to CO2 as opposed to H2O) of Pt/CeAZrO(2) catalyst is mainly due to the high oxygen storage capacity of Ce-ZrO2 and nano-crystalline nature of cubic Ce0.8Zr0.2O2.