Abstract: Circuit analysis is employed to investigate the maximum transfer distance problem in magnetic resonance wireless power transmission systems.It is described firstly the frequency splitting phenomena that are closely related to the maximum transfer distance problem.Next,the splitting equation,the ridge equation and the trough equation are defined,and the critical splitting point is found through the ridge equation.The maximum transfer distance is uniquely determined by the critical splitting point,and the relationship between the maximum transfer distance and the key system parameters is elucidated.Finally,above theory is validated by the experimental data from the literature.