The surface structure of copper (Cu) electrodes is a key factor determining product selectivity during electrochemical reduction reaction of carbon dioxide (CO2ERR). We investigated the influence of the chemical etchant on the Cu surface morphology as well as the product selectivity by CO2ERR. The hydrocarbon selectivity in CO2ERR was strongly dependent on the chemical etchant. Moreover, the construction of Cu surface for enhanced ethylene (C2H4) formation was also achieved by chemical etching treatment.