Ground fault location in distribution line is specified the restricted area by sequential fault detection system. Then, ground fault location is identified by detecting magnetic field originated discharge current from direct pulse device on electric pole. It needs much time to identify ground fault location due to involving works on electric pole. Recently, introducing switch with built-in sensor (ITSW) is considered on the purpose of efficient operation against amount of diffusion of Photovoltaic Power Generation Systems Source. For the purpose of introducing IT switch, ground fault location detecting method is studied by IT switch. As one of the means, it is studied the shortening of ground fault location detecting hours. For example, ground fault location is identified by the difference in arrival time of ground faults surge current from different measuring points, classification of characteristics from wave form in ground fault current, and so on. In this paper, we propose that it is estimated the brunch point from the high frequency component by measuring the wave form of ground fault current in transient state of both feeding direction and terminal point, and is verified by ATP simulation to check the validity of proposed method. In addition, we study the improvement of proposed method precision.