Abstract: A series of CuZnAl slurry catalysts were prepared by the complete liquidphase technology. The influence of heat treatment atmospheres with different proportions of CO2 on the performance was investigated and the catalysts were characterized by TPR, BET, XRD and XPS. The results show that introduction of CO2 into heat treatment atmosphere influences obviously on the structure of catalysts before reaction but less on that of the ones after reaction.The reason is under the conditions of reaction, the bulk structure, pore structure and surfa ce state will voluntarily go to same. The heat treatment atmosphere with different content of CO2 influences obviously on the reductive performance of the catalysts, low reductive temperature is corresponding to high DME spacetime yield and right amount of Cu metal and Cu2O to high CO conversion. The introduction of CO2 into heat treatment atmosphere restrains the watergas shift reaction, raising the DME selectivity. The proper amount of CO2 in the heat treatment atmosphere can result in the increase of DME space-time yield. In this work, when the content of CO2 in the heat treatment atmospheres is 50%, the performance of catalysts is best.