The assembly of proton exchange membrane fuel cell (PEMFC) is the important factor for the performance. The achievement of proper design will improve the pressure distribution and the electrical contact resistance between fuel cell parts. The assembly pressure affects the contact behavior between of bipolar plate and gas diffusion layer (GDL). In this study, finite element analysis (FEA) was used to analyze the behavior of single cell fuel cell under the variation of assembly pressure. It shows 3D of deformation, and the compression pressure every part of the fuel cell components. The simulation varied the torque assembly from 1 Nm to 3 Nm with increment 0.5 Nm. The simulation using FEA shows that high assembly pressure also affects to the high deformation and stress in the components of fuel cell. This phenomenon affects to the performance of PEM fuel cell.