A method to identify feature points associated with the heart valve movement, heart contraction or cardiac hemodynamics is revealed. The mechanocardiography (MCG) is a technology that makes use of vibrational waveforms acquired using at least one gravity sensor attached on one of the four heart valve auscultation sites on the body surface. The data of the electrocardiography (ECG) is recorded simultaneously with the MCG. The feature points are identified by comparing P, R and T points of synchronized ECG with the MCG spectrum. By the time sequences and amplitudes of the feature points, the method provides additional clinical information of cardiac cycle abnormalities for diagnosis.