The heart valve auscultation zone refers to the location where the heart valves are most clearly heard on the body surface when they are open and closed. The second aortic valve auscultation zone, located at the third intercostal space on the left edge of the sternum; 5, the tricuspid valve auscultation zone, located at the fourth and fifth intercostal spaces on the left edge of the sternum. The identification of the nature of valve auscultation is usually used to determine whether a patient has a valve lesion. Therefore, the sequence of heart valve auscultation is generally performed in the mitral auscultation zone, then to the pulmonary valve auscultation zone, the first aortic valve auscultation zone, the second aortic valve auscultation zone, and the tricuspid valve auscultation zone.