Signal sine wave high frequency and signal leakage current is measure by current sensor, at the late of the ground line. By data measure form current sensor will send input Data Acquisition (DAQ), already connect with computer, For apply analysis with MATLAB programs by method analysis for Fast Fourier Transform (FFT). The trial result has presented, When an leakage current at the 1st load, that FFT graph analysis from MATLAB programs result show signal spike is 50 Hz with 1.3 kHz, When an leakage current at the 2nd load, that FFT graph result show signal spike is 50 Hz with 2.1 kHz, When an leakage current at the 1st load, and he 2nd load at the same time, that FFT graph result show signal spike is 50 Hz, 1.3 kHz and 2.1 kHz .