Due to fast life style Heart related problems are increasing day by day and it's very important that disease related to heart can be diagnosed easily by simple medical techniques. These diseases can be diagnosed by ECG (Electrocardiogram) signals. ECG is used for measurement of electrical potentials with the help of contact electrodes, thus it is treated as one of the important signals. The ECG recording is often deteriorated by several factors such as power line interference and baseline wander noise. Various noises have to be removed for better clinical evaluation. This paper gives the different way in which noise occurs & methodologies to remove such addition in the ECG signal. Signal to noise ratio (SNR) is measured from ECG signal and comparison is made with the performance of different methods used for removal of ECG noise.