CuO-CeO₂ catalysts were prepared by coprecipitation and used for selective oxidation of carbon monoxide in the presence of excess hydrogen and carbon dioxide. The catalysts were characterized by means of XRD, XPS and H₂-TPR. The CuO-CeO₂ catalysts exhibited high catalytic activity in selective oxidation of CO, showing markedly enhanced catalytic activities due to the solid solution of Cu-Ce-O. Only CeO₂ peaks were shown in all the catalysts, and as the increase of Cu loading, the lattice constant of CeO₂(111) decreased.