The full scientific name of ACEI class antihypertensive drugs is angiotensin-converting enzyme inhibitors, the most commonly used drugs, including the most common captopril, which is the most commonly used in the early years, now relatively more used called fosinopril, benazepril or ramipril, and perindopril. These antihypertensive drugs are often used in clinical practice, and the action of these drugs is characterized by a very good antihypertensive effect for mild to moderate hypertension, which allows the patient’s blood pressure and heart rate to reach a more reasonable level. Its adverse reactions, the most common is cough adverse reactions, irritating dry cough, no sputum, these drugs not only have antihypertensive effect, and often after some patients have coronary heart disease, doctors also prescribe him these drugs for treatment, blood pressure is often not high, it is for these patients treatment is not to lower blood pressure to treat, it has a cardioprotective effect.