Electrochemical reactions of surface-fluorinated petroleum coke (petroleum coke heat-treated at 2800°C: PC2800) electrodes have been investigated by cyclic voltammetry and XPS analysis. Three reduction peaks were observed at 2.31V, 0.70–0.74V and 0.46–0.59V versus Li/Li+ in the first reduction curves of cyclic voltammograms. The peak at 2.31V appeared only for PC2800fluorinated at 500°C. Two reduction peaks were also observed at 0.71V and 0.59V for surface-oxidized PC2800. The surface oxygen was increased through the electrode preparation process while the amount of surface fluorine was reduced by hydrolysis. The reduction peak at 2.31V shows the reduction of fluorine bonded to basal plane of graphite, and those at 0.46–0.59V are due to the reduction of ethylene carbonate (EC) as a solvent. The peak at 0.70–0.74V would be also attributed to the reduction of EC on the hydrophilic sites of partly oxidized PC2800 surface.