Ａ series of Cu2+-substituted composite metal oxides LaMnO3 were prepared by improved amorphous citric precursor method(IACP)， characterized by XRD ,IR,BET and SCM , tested the performance of ethanol to n-butanol and n-butanal without oxygen. The results showed that the Cu2+-substituted products could reserve the perovskite-type crystal structure, and crystalline phases of CuO, MnO2 and La2O3 appeared when the amount of copper increased. The aberrations of B-substituted crystal structure was larger than that A -substituted ,and B-subsituted oxides which showed better activity than the A-subsituted. Among all the catalysts, LaCu0.3Mn0.7O3 exhibited the highest catalytic activity. Under the tempereture of 500℃, the conversation of ethanol was 55.18%, and the selectivity of n-butanal and n-butanol was 41.30% and 24.09%, respectively.