In this paper, the dynamic mathematical model of a proton exchange membrane (PEM) fuel cell is presented. Dynamic performance of a PEM fuel cell system by experimental and simulation using matlab/simulink is investigated. The V-I load characteristics of a 1.2 kW PEM fuel cell are presented. Result shows that the starting current of the PEM fuel cell operated at rated load reaches to approximately twice of its rated current in just less than 0.015 second before it reached to its steady state condition. Step change load responses of this PEM fuel cell were experimented and simulated. It was found out, from the results obtained, that PEM fuel cell had a very fast response to load changes. Moreover, results show that the experimental and the result computed by using the simulation of the model are very close to each other which validates the model. Hence, this model could be used to implement a controller design in order to come up with an optimal and efficient operation of PEM fuel cell. Based also on the results, a suitable power conditioning can be constructed and designed for safe and reliable operation of PEM fuel cell especially in integrating and connecting it to a hybrid wind/PV distributed generation system.