The circular slice method is one of the normal methods for analyzing slope stability, which assumes that the stabilities of individual slices are equal and equaled to that of whole slope and belongs to an imprecise limit equilibrium method of rigid body with some irrationality. In this study, a simple slope was used as a model to study the features of force transferring between individual slices,discipline of slippage and compati-bility condition of acceleration with improved slice method when the slope is in destabilization and the stabili-ties of individual slices are not equal. A theoretical formula for calculating interaction forces and the stable coefficient of individual slices under instable states was then deduced. The calculation of practical sample demonstrates that this method can be used to analyze accurately the stability of whole slope,as well as to re-veal the stable circumstance of part slices within a slope. It maybe possesses some important referential val-ues for practical construction.