Abstract: The effects of the beta term on the typhoon structure are examined within the linear framework in terms of an analytical method of 2D Fourier representation and numerical experiments with a beta-plane quasi-geostrophic barotropic model. Results show that due to the joint effects of the difference in Rossby phase velocities and the dispersion of typhoon energy,the maximum wind velocity varies with time reasonably increasing rather than without limit. On the one hand.the nonlinear advection accelerates typhoon vortex damping,and on the other,the high pressure system formed downstream due to energy dispersion makes it easy to maintain.