The reactivity of Pd/Al2O3-CuO catalysts was not enhanced with the increase of CuO contents and the Pd/AlCu50(1) performed best in ethanol oxidation reaction. The more PdO and less PdCl2 were conducive to the oxidation reaction. The larger quantity of Al3+ was conductive to the transformation from gaseous oxygen to active oxygen species and could provide more adsorption sites. The Pd-Cu alloy decreased the reduction temperatures of Pd and Cu oxides and enhanced the interaction between Pd and Cu species. Furthermore, the large content of high crystalline degree lattice plane (-111) might be beneficial for the higher reactivity.