For the stable and high performance operation of the methanol fuel cells, it is essential to maintain water balance on the cathode successfully due to control of air flow rate.Generally, ion exchange membrane and sulfuric acid are normally used as electrolyte of fuel cells. Then, it was found that the increase of air flow rate was necessary to maintain water balance on the cathode successfully when high molecular polymer electrolyte was used and sulfuric acid concentration in anolyte was lowered.Therefore, this paper studied the consumption rate of methanol and water on the anode in case of with and without sulfuric acid, as parameters of current density, air flow rate, cell temperature and methanol concentration.As a result of the experiment, following things were cleared, (1) In the relation to air flow rate, water permeated into the cathode through the electrolyte layer from the anode in case of water shortage in the cathode.(2) The water permeability rate in case of without sulfuric acid became 2.8 times greater than that of with sulfuric acid.