In a tissue characterization of local myocardium, the ultrasonic integrated backscatter (IBS)  is known well. The validity of IBS is confirmed clinically. However, the ability of diagnosis is not adequate for the light myocardial disease. Because IBS averaged intensity of reflected ultrasound (about 3 micro second = 2.3mm) in the region of interest, and it cannot measure the cardiac phase dependent spectrum change of radio frequency (RF) signal from muscular tissue. We are investigating the new method to evaluate regional myocardial function much precisely using ultrasonic RF signal, and we have proposed the automatic tracking method using "Correlation Method weighted with Confidence (CMC)" . Our tracking system can detect the motion of the specified local myocardium with high accuracy, and it can find the regional thickness change (transmural difference from endocardium to epicardium) during one cardiac cycle in normal and abnormal human heart.