Abstract: The health checking tools represent one of the most important things in the lifestyle for investigative and evaluation of the body. The ECG signals are essentially refer to the function of the heart, several features are extracted from ECG signal may carry significant information about the body health, therefore, it's very important to get pure and clean signals. The interference signal from power line noise represent one of the most significant problem. The power line interference signal has high amplitude with 50 or maybe 60 Hz. The notch filter is used to cut the power line signal from raw ECG signal to reduce the effect of this signal but this method not very acceptable due to cut high range of the raw signal and remove some useful information about original ECG signal, therefore, modified blind source separation technique is presented to separate this signal from mixture ECG signal without effect on the original ECG signal and no needs any reference input to detect or cancel the power line noise signal. Simulated and real ECG data are taken based on MIT-BIH databases for recording different ECG data. The gotten result can be used for medical analysis by the doctor and supportive in discovery numerous defects in the heart.