An electrochemical method was developed to analyze the quantity and oxidation state of exposed Cu impregnated in porous carbon. Carbons of different Cu contents were prepared from Cu(NO3)(2) impregnation followed by heat-treatment at different temperatures. X-ray diffraction has shown the transformation of the deposited Cu from high to low oxidation states upon increasing the treatment temperature. The crystalline size was also found to increase with temperature. A linear potential sweep from the open-circuit potential of the carbons to -1.4 V vs. SCE in KOH was able to directly estimate the amounts of CuO and Cu in the carbon from the charge consumed in associated reduction peaks. All the Cu species can be oxidized to CuO at 0.2 V vs. SCE, and this was employed to estimate the amounts of total Cu and Cu2O. The present work has demonstrated that because of the conductive feature of carbon, electrochemical measurement becomes an important option to quantitatively analyze metals of different oxidation states present in carbon. (C) 2004 The Electrochemical Society.