Abstract： Objective To investigate the influence of different medication time on morning blood pressure surge(MBPS) in patients with essential hypertension.Methods From June 2016 to May 2017,100 patients with essential hypertension at the Second Outpatient Department,Beijing Anzhen Hospital,Capital Medical University were enrolled as observation group;100 essential hypertension patients at Department of Cardiology,Beijing Anzhen Hospital,Capital Medical University were enrolled as control group.The control group took telmisartan tablets 800 mg at 06:00-07:00 in the morning.The observation group took telmisartan tablets 800 mg at 20:00-21:00.Clinic blood pressure,24 h mean blood pressure and MBPS were analyzed before and 12 months after treatment.Results After treatment,clinic systolic and diastolic pressure,24 h mean systolic and diastolic pressure were significantly lower than those before treatment in both groups [control group:(143 ± 10) mmHg vs (154 ±+ 11) mmHg,(84 +9) mmHg vs (99 ±+ 5) mmHg,(133 ± 10) mmHg vs (147 ± 11) mmHg,(77 ± 11)mmHg vs (88 ± 7) mmHg;observation group:(134 ± 10) mmHg vs (156 ± 10) mmHg,(81 ± 9) mmHg vs (96 ± 9) mmHg,(129 ± 11) mmHg vs (145 ± 10) mmHg,(76 ± 10) mmHg vs (90 ± 8) mmHg] (all P ＜ 0.05).After treatment,the increase ratio of MBPS was significantly lower than that before treatment [control group:32.0％ (32/100) vs 54.0％ (54/100);observation group:14.0％ (14/100) vs 47.0％ (47/100)];the decrease ratio of MBPS in the observation group was significantly higher than that in the control group [70.2％ (33/47) vs 40.7％ (22/54)] (all P ＜ 0.05).Conclusion Taking hypotensor at evening(20:00-21:00) can reduce clinic blood pressure,24 h average blood pressure and MBPS.