Electrochemical reduction of carbon dioxide was carried out on copper foil electrodes modified with nanopores on the surface. Such nanopores modified structure was obtained through an alloying−dealloying process. Scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy confirmed the formation of alloy layer and the final nanoporous morphology of such copper electrodes. When used in electrolysis process, the as-prepared nanoporesmodified electrodes can suppress the Faradaic efficiency toward methane to less than 1%, while keeping that of ethylene in a high level of 35% in aqueous 0.1 M KHCO3 solution under −1.3 V (vs reversible hydrogen electrode), thus revealing a remarkable selectivity toward ethylene production. The high yield of ethylene can be ascribed to the exposed specific crystalline orientations.