A gamma -alumina-supported copper-manganese oxide catalyst prepared by an impregnation method was used for DME synthesis from CO/H-2 (syngas). The Cu-Mn/gamma -Al2O3 catalyst exhibits high catalytic activity in CO hydrogenation. The effect of the loading amount of Cu, the ratio of n(Cu)/n(Mn) and the reaction conditions on the activity and selectivity to dimethyl ether (DME) from CO/H-2 (syngas) were investigated. The activity was found to increase with increasing surface area of metallic copper to some extent, but it is not a linear relationship. This indicated that the catalytic activity depends on both the metallic copper area and the synergy between the copper and manganese oxide.