Safe and reliable operation of a fuel cell requires proper management of the water and heat that are produced as by-products. Most of the current models for the cell used for an analysis of the fuel cell system are based on the empirical polarization curve and neglect the dynamic effects of water concentration, temperature and reactant distribution on the characteristics. The new model proposed in this paper is constructed upon the layers of a cell, taking into account the following factors: (1) dynamics in temperature gradient across the fuel cell; (2) dynamics in water concentration redistribution in the membrane; (3) dynamics in proton concentration in the cathode catalyst layer; (4) dynamics in reactant concentration redistribution in the cathode GDL. Simulations have been performed to analyze the effects of load currents on the behaviors of the fuel cell. In the future, the fuel cell model will be extended to a stack model and integrated with system models. All of the models will be implemented on a real time system that optimizes the computation time by a parallelization of solvers, which provides an environment to analyze the performance and optimize design parameters of the PEM fuel cell system and components. (c) 2005 Published by Elsevier B.V.