Phenol oxidation in aqueous solutions was carried out in a pH range of 7-12 using cyclic votlammetry (CV) and differential pulse voltammetry (DPV) studies oil a glassy carbon electrode. Peak potentials are found to be distinct for each pH Value. A linear relationship is observed between the peak current and the concentration ranging from micro- to milli-molar levels. The peak current is found to be proportional to the concentration of phenol up to 5 muM that allows determination of unknown concentrations of phenol down to 5 muM. Using DPV technique, the phenol concentration is detected up to a concentration of 0.5 muM.