Ambulatory blood pressure monitoring is the automatic measurement of blood pressure within 24 hours with the instrument, which reflects the blood pressure is objective, accurate, is the closest to the blood pressure of daily life. We usually measure blood pressure once is called occasional blood pressure, ambulatory blood pressure monitoring can reflect many occasional blood pressure incomparable indicators: 1, circadian blood pressure rhythm: normal people 24-hour dynamic blood pressure curve shape is a double peak a valley, 6-10 a.m. and 4-8 p.m. are two peaks, the lowest at night, is the valley. If the blood pressure rhythm is abnormal, the incidence of target organ damage to the heart, brain and kidney is high and serious; 2, 24-hour blood pressure fluctuations: the greater the degree of blood pressure fluctuations, the more serious the target organ damage; 3, the average value of ambulatory blood pressure: that is, the average value of 24-hour blood pressure, the average value of daytime blood pressure should be <135/85mmHg, the average value of nighttime blood pressure should be <125/75mmHg, the average value of blood pressure directly affects hypertension The mean blood pressure value directly affects the prognosis of patients with hypertension; 4. Blood pressure load: Blood pressure load is the percentage of the number of times the blood pressure exceeds the normal value of the total number of measurements. Blood pressure load is more predictive of target organ damage, blood pressure load > 40% is an indicator of hypertension with target organ damage, and should be actively treated; the application of ambulatory blood pressure monitoring can also guide the selection and dose adjustment of antihypertensive drugs, evaluate the antihypertensive efficacy, and can identify “white coat hypertension”, so hypertensive patients with ambulatory blood pressure monitoring Therefore, ambulatory blood pressure monitoring in hypertensive patients has important clinical significance.