The research aims to study the effect of the distribution water on Proton Exchange membrane fuel cell (PEMFC), and the relationship of membrane thickness and the effects of changes in thickness depending on the amount of water contained within the membrane. The research also aims to change the effect of humidity on the effectiveness of the membrane proton through the diffusion coefficient and the coefficient of the flow electral osmotic. The research includes the study of humidity on the cell performance at constant temperature and its effect on the input interface.