ECG is a very important tool for the primary diagnosis of heart disease;   it gives a full picture about the electrophysiology of the heart and the ischemic changes that may occur like the myocardial infarction, conduction defects and arrhythmia. For this reason ECG signal must be clearly represented and filtered to remove all noise and artifacts from the signal. ECG is one of the biosignal that is considered a non-stationary signal and needs a hard work in denoising. In this paper a new approach  of denoising of EGG signal is proposed in using Wavelet Transform WT. Different ECG signals are used to evaluate the method using MATLAB’ software. The presented method showed better results than conventional methods particularly in ECG signal case.