Objective To explore the impact of amlodipine ,enalapril ,telmisartan and metoprolol on the blood pressure variability (BPV) in the patients with essential hypertension(EH) .Methods 120 patients with EH were divided into the amlodipine ,enala-pril ,telmisartan and metoprolol groups with 30 cases in each group .The ambulatory blood pressure monitoring (ABPM ) was adopt-ed and BPV before treatment and after 8-week treatment was observed .Results The anti-hypertensive effect of amlodipine and telmisartan was more obvious ,and the anti-hypertensive effect of metoprolol on the diastolic blood pressure was significant ,but the anti-hypertensive effect of enalapril was unobvious .Amlodipine and telmisartan lowered BPV at most time .Amlodipine mainly re-duced the daytime diastolic BPV ,while telmisartan reduced the night BPV significantly ;metoprolol and enalapril increased the day-time systolic BPV and decreased the nighttime BPV in 24 h BPV .Conclusion Amlodipine ,enalapril ,telmisartan and metoprolol can reduce the blood pressure in the patients with EH ,but their influences on BPV have difference .The impact of different anti-hyper-tensive drugs on BPV is inconsistent with the anti-hypertensive effect .