Common adverse reactions of ACEI antihypertensive drugs, mainly the following: First, allergy, manifested as itching of the skin, chest tightness, breathlessness and so on. Second, edema, manifested as edema of bilateral lower limbs, and angioedema can occur in severe cases. Electrolyte disorders, mainly hyperkalemia. Fourth, abnormal renal function, manifested as elevated blood creatinine and urea nitrogen. Fifth, blood pressure reduction, mainly manifested as systolic blood pressure lower than 90mmHg or diastolic blood pressure lower than 60mmHg, seen in patients taking drugs overdose, there are other adverse reactions, but rare.ACEI antihypertensive drugs as a common clinical antihypertensive drugs, which are widely used in patients with hypertension, diabetes mellitus, nephropathy, etc., as long as in the regular hospital internist and the pharmacist’s guidance to take, it is safe and reliable.