A two dimensional PEM fuel cell model is developed, which considers transient of mass, heat and momentum transfer in the gas channels and diffusers at both the anode and cathode sides of the PEM fuel cell. This modelling visualizes the effect of permeability on the dynamic behaviour of the velocity and pressure profiles in the parallel flow field in the transient model of PEMFC fuel cell. The 2D numerical simulations were obtained using the finite volume method. The results demonstrate the difference between the flow in a continuous medium and a porous medium. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.