The abundant amount of carbon dioxide increases the interest in CO2 reduction research. There are a lot of methods to reduce CO2 and one of them is electroreduction. Electroreduction of CO2 is a promising technique, because it can transform CO2 directly into hydrocarbon. In this research, electroreduction of CO2 was studied using boron doped diamond (BDD) modified with cuprous oxide (Cu2O) as working electrode. Modification of BDD was done using chronoamperometry technique and characterized using Scanning Electron Microscope (SEM), Energy Dispersive X-Ray Spectroscopy (EDS), X-ray Photoelectron Spectroscopy (XPS), and Cyclic Votammetry (CV). The resulting product was analyzed using High Performance Liquid Chromatography (HPLC) and Gas Chromatography (GC) for liquid products and GC with TCD detector for the gas product. Results shown the BDD modified with cuprous oxide electrode produces the most variative products than other electrode, which are formic acid, ethanol, and acetic acid. The most produced product from the reduction is acetic acid in concentration 29.8 mg/L and %faradaic efficiency is 68.2 % using Cu2O-BDD electrode in -1.5 V potential.