Abstract: The purpose of this paper is to discuss stability structure and bifurcation of phase path characteristics of synoptic scale system.The analysis results show that catastrophe of the synoptic scale disturbance can be caused by the nonlinear effects of barotropic,baroclinic instability and advection of ambient large scale flow.Also,foregoing nonlinear effects on velocity of development and decay of the system are presented in the processes deviating from equilibrium state or approaching to it.It has been found that there is a resonance phenomenon between the time-oscillation of heat source and the atmospheric disturbance.