CuO/CeO2 catalysts prepared by co-precipitation, deposition-precipitation and impregnation methods were extensively investigated for CO oxidation reaction. It was shown that the catalytic behaviors of CuO/CeO2 catalysts greatly depended on the preparation routes, which caused significant differences in the redox properties and the dispersion of copper species. The remarkable redox ability of CuO/CeO2 at lower temperatures was found to play an essential role in CO oxidation reaction. The catalysts prepared by co-precipitation exhibited the highest catalytic activity in CO oxidation with CO total conversion at 85 degreesC. The structural characters as well as the redox features of CuO/CeO2 catalysts were comparatively investigated by XRD, TPR, cyclic voltammetry and XPS measurements. The discrepancies in the dispersion of copper species and the degree of interaction between copper species and ceria determined the reversible redox proper-ties, and consequently the catalytic performance. (C) 2004 Elsevier B.V. All rights reserved.