Abstract: The Multi-Periodic-Solutions of a nonlinear dynamic system means that there existseveral periodic solutions in state space at the same time, it is determined by the nature of thenonlinear dynamic system and is an important characteristics of the nonlinear dynamic systemdiffering from the linear systems. Today the research of linear system is mature, but that of nonlinear system is very difficult. The problem of Multi-Periodic-Solutions of the nonlinear dynamicsystem is a very important and very complex prob...