This paper proposes an effective Fault Detection Technique in distance relaying using discrete current samples. The original signal under fault consists of two parts namely, normal and disturbance part. The fault detection is easily achieved as the disturbance part of the signal produces an irregular shape compared to the shape produced from the normal part of the signal. By selecting suitable threshold value, the starting point of irregular part can be found. The proposed algorithm is so effective and easy when compared to other algorithms. Results are carried out in MATLAB/SIMULINK software.