Abstract: Cardiac neural plays a crucial role in cardiac function.Cardiac diseases usually cause damage to cardiac autonomic function.¹²³I-metaiodobenzyl-guanidine imaging is an ideal evaluation method of cardiac autonomic function.It evaluates the damage to the sympathetic nerve of various cardiac patients, guides pharmacologic therapy, and determines the necessity of mechanical devices and cardiac transplant. The radiotracer imaging allows visualization and quantitative measurements of the cardiac lesion.