There are about 230 million people with hypertension in China, with 10 million new cases each year, and antihypertensive drugs are an effective means of controlling blood pressure. The incidence of hypertension is gradually increasing, and it is the most important risk factor for stroke. For patients with hypertension, the correct timing of medication is very important. Blood pressure fluctuates in the 24 hours of a day in a state of “two peaks and a valley”, i.e., it is highest from 9:00 to 11:00 and from 16:00 to 18:00, and it begins to fall slowly from 18:00 to the lowest at 2:00 to 3:00 the next morning. Some patients with hypertension have a rapid rise in blood pressure when they wake up in the morning, which is called the “morning peak phenomenon”, and for these patients the earlier they take their daily antihypertensive medication the better. A small number of hypertensive patients have the opposite situation: their blood pressure rises at night after they go to sleep, and is relatively stable during the day, so they should take their antihypertensive medication after dinner. Patients with mild hypertension should not take medication at night before going to sleep, and patients with moderate to severe hypertension can only take one-third of the daytime amount, because the night for physiological hypotension to lower blood pressure, which leads to insufficient blood supply to the cerebral arteries and the formation of cerebral thrombosis on the basis of cerebral atherosclerosis. Hypertension medication dosing time recommendations: 1 day to take one antihypertensive drugs (including controlled-release slow-release preparations) more in 7: 00 dosing is good. For antihypertensive drugs taken twice a day, it is better to take them at 7:00 and 14:00, so that the peak time of drug action coincides with the two peak times of natural fluctuation of blood pressure, thus better lowering blood pressure. Alpha-blockers (such as terazosin, doxazosin, etc.) are recommended to be taken at bedtime because they are more likely to cause postural hypotension. In addition, there are a few special cases, such as the phenomenon that blood pressure does not change significantly during the day and night, or even low blood pressure during the day and high blood pressure at night. Therefore, patients with hypertension must go to the hospital for blood pressure monitoring to find out the changes in their blood pressure and then personalize their medication.