The electro-deoxidation of unexfoliated GO has been carried out in aqueous solution. The electro-deoxidation of GO took place from -0.4 V vs. Ag/AgCl in KCl solution and showed the best results at -1.0 V. The pH value of the KCl solution after the electro-deoxidation increased up to 11.35 from the neutral electrolyte (pH = 7.20) due to the build-up of OH- in the electrolyte, which originates from the oxygen functional groups removed from GO by the electro-deoxidation. The neutral solution was more effective than the alkali solution for the electro-deoxidation of GO.