Several genetic systems are involved in the pathophysiology of CAD, among these, angiotensin I-converting enzyme (ACE) plays role in modulating vascular tone and electrolyte balance by hydrolyzing angiotensin I to angiotensin II, which is a potent vasopressor and aldosterone-stimulating peptide [5], the individual variation of plasma ACE levels is largely affected by polymorphism of the ACE gene. This evidence concerns the gene ACE and coronary artery disorder.