Highly selective reduction of CO2 to C-2 compounds such as CH3CHO, C2H5OH, and C2H4 has been achieved on CuAg alloy electrodes by pulsed electroreduction. The faradaic efficiencies of C-2 compounds produced on CuAg alloy electrodes were varied with the atomic ratio of Cu to Ag. The total value of faradaic efficiencies for these Ct compounds was 53.2% for the pulsed electroreduction on a CuAg alloy electrode (Cu/Ag = 28/72) with an anodic bias of V-a = -0.4 V and a cathodic bias of V-c = -2.0 V bias Ag/AgCl. It was Found that the formation of an oxide layer on Cu and the desorption of intermediates on AE under anodic bias were I;ey factors for the selective reduction of CO2 to C-2 compounds on CuAg alloy electrodes.