Complexing agents were introduced to Cu-ZnO/Al2O3 catalysts prepared by complete liquid-phase technology. Characterization shows that the introduction of appropriate proportion of complexing agents can stabilize copper ions and increase the catalystic surface basicity. As a result, the selectivity of ethanol was enhanced in the CO hydrogenation reaction. Activity tests indicate that the Cu-ZnO/Al2O3 catalyst effectively catalyzed syngas conversion to ethanol in a slurry reactor, while CO conversion of 17.0%, ethanol selectivity of 24.5% reached under the reaction conditions of 250 degrees C, 5.0 MPa, H2/CO = 1, gas hourly space velocity of 360 ml/(g cat center dot h) and without alkali metals promoter.