A model of PEMFC is developed that captures dynamic behavior for control purposes. It analyzes in detail the influence factor of voltage of PEMFC. The model is mathematically simple, and accounts for the essential phenomena that influence the PEMFC performance. The partial pressure of hydrogen and oxygen can be found using the laplace transform and differential form of ideal gas state equation. It is assumed that the mixture ratio of hydrogen and oxygen in the reaction are constant, the dynamic lumped model of PEMFC is proposed. The model is verified by comparing the experiment data with simulation result of model. On the basis of the dynamic model, the partial pressure and voltage are analyzed when when the load current suddenly changes.The research about lumped model has important significance to the research of the distributed generation network in various performances and has guiding meaning to the structure design of fuel cell.