Abstract: The catalytic performance of LaMnO3, La-Mn1-x-CuxO3, La0.8Sr0.2-Mn1-x-CuxO3, and La0.8Ba0.2-Mn1-x-CuxO3 for the title reaction was tested in the gas mixture of 1% CO, 0.5%～2% O2, 50% H2 in N2 and at a space velocity of 40 000 mL·g－1·h－1. The results show that the partial substitution of Cu for Mn in LaMnO3, and the partial substitution of Sr or Ba for La in La-Mn1-x-CuxO3 can enhance its catalytic activity. Among the catalysts investigated, the highest catalytic activity was observed over La0.8Sr0.2Mn0.5Cu0.5O3 catalysts: CO was completely converted to CO2 at 155 ℃ with a corresponding selectivity of 54%, which is close to the catalytic performance of some platinum catalysts. The conversion of CO was lowered with the addition of 15% CO2 in the reactant gas. The addition of 10% H2O in reactant gas reduced the CO conversion more markedly.