Abstract: Pulse Coupled Neutral Network (PCNN) can be implemented on many application areas such as image processing effectively.But little researches are about dynamic characteristics of PCNN in present,as a result,the determination of parameters for PCNN is very difficult in the specific application.In order to further exploit the PCNN model application development,period characteristics of a discrete PCNN model are analyzed theoretically and deduced by formula in detail.Simulation results demonstrate the correctness of the analysis conclusion.