The current-voltage curves of a composite bipolar membrane (CBM) were experimentally measured for the various mole fractions of methanol-water, ethanol-water, and n-propanol-water mixed solution systems. In each solution system, 0.1 mol/L LiCl was used as the electrolyte. The experimental results showed that a CBM has the characteristics of a bipolar membrane. The current-voltage characteristics were analyzed using Mafe and Ramirez＇s ion transport theory by applying the chemical reaction model in the intermediate region, and the theoretical calculations were able to well explain the experimental results. The current-voltage curves show that the maximum local effective value of a CBM resistance will increase with an increase in the mole fraction of alcohol. This phenomenon is due to the fact that the dissociative ability of an alcohol is much weaker than that of water; thus, the current is mainly induced by the water splitting. However, methanol splitting was observed in the case of the LiCl-methanol solution because of its somewhat large autoprotolysis constant.