Abstract: A two - dimensional model of water transport is developed to investigate the distribution of water in the membrane, the distribution of the rate of water transport, the distribution of current density in the proton- exchange membrane fuel cell(PEMFC) . The effects of cell temperature, pressure difference between cathode and anode, humidification and thickness of membrane on water transport and distribution of water in the membrane are studied systematically. The conclusions from the model are as follows: ① If the anode is humidified, the water content on the anode side membrane in the reactant gas entrance can be increased; ② The thinner the membrane used, the higher the water content in the membrane;③ The higher the anode is humidified, the more water will migrate from anode to cathode.