The electrochemical reduction of carbon dioxide (CO₂) has been treated as a clean and efficient method to face global challenges which are resulted from extra emission of CO₂ into the atmosphere. In CO₂ electroreduction, Sn metal was reported to be the most active electrode towards CO₂ electroreduction in aqueous electrolytes, producing formic acid [1]. However, the technology advances are still not sufficient for practical applications. Moreover, the deactivation of Sn metal electrodes in CO₂ reduction still needs to be improved [2]. Developing new material synthesis technology to give innovative new catalysts with optimal performance is no doubt the priority. In the effort to improve catalytic activity and stability, two important aspects of catalyst materials have to be improved, which are the composite materials and nanostructured catalysts, respectively. Kanan et al [3] found that metastable Tin oxides (SnOx/Sn) can participate in the CO₂ reduction pathway on Tin metal electrodes (Sn) by providing chemical functionality that stabilizes the incipient negative charge on CO₂ or by mediating the electron transfer directly, therefore the catalytic activity for CO₂ electroreduction was greatly enhanced relative to a bare Tin metal electrode. The unique properties such as high specific surface area can provide easy diffusion path lengths for substrates to access, leading to faster kinetics [4]. In view of these facts, we here report the synthesis and properties of novel SnO₂-CuO nanocomposites with an average diameter of about 400 nm, which exhibit the perfect catalytic activity to CO₂ electroreduction and high Faradaic efficiency.