A series of Pd/Ce0.2Y0.8O2-delta catalysts were prepared and tested for CO and CH4 oxidation. It is found that the Pd/Ce0.2Y0.8O2-delta catalysts are thermal stable, and the catalytic activity enhances with increasing calcination temperature. The enhancement of the activity is due to the decomposition of surface carbonate species and the increase in average oxidation state of Pd.