Abstract: First, an extended petri net based model of radar network system was proposed. By analyzing the structure of the model, not only the problem of synchronization between radars was solved, but also the way to avoid conflicts in the system was presented. Then extend Petri net was combined with queuing theory to describe some statistical performance of the system quantitatively. Finally, a simulation experiment was carried out by using the proposed model. Consequently, extended petri net was a powerful tool to model and analyze radar network system, especially in structure optimization and effectiveness assessment.