Abstract: In this paper, using the method of cut off spectrum, the nonlinear properties of the sheared magnetohydradynamics at the boundary layer of the magnetosphere are investigated. The primary results are: (1) the perturbation of flow causes the K-Hinstability; (2) the system is sensitive to the initial conditions, this will lead to purturbations of the system and is an essential reason why the dynamic property of the magnetopause is difficult to predict; (3) the kinematic viscoisity and the interactions between flow and magnetic field may make the transfer of the momentum and energy; (4) the energy from outside may be transported into the system by the kinematic viscosity and couplings between flow and magnetic field.