OBJECTIVE： To observe clinical efficacy and safety of Ginkgo biloba extract combined with olmesartan medoxomil in the treatment of essential hypertension， and to discuss its effect on the expression of serum protein. METHODS： 98 patients with essential hypertension were selected and randomly divided into observation group A and observation group B， with 49 cases in each group； 40 healthy volunteers were included in control group. Observation group A was given Olmesartan medoxomil tablet 20-40 mg，po，qd； observation group B was given Olmesartan medoxomil tablet 20-40 mg，po，qd+ Extract of G. biloba leaves tablet 40-80 mg， po， bid. Treatment course lasted for 4 weeks. Blood pressure （SBP and DBP）， TCM symptom score， the repetitiveness and resolution ratio of 2-DE spectrum， protein differentiation expression point， related information of differentiation expression protein in 3 groups and ADR of observation group were observed. RESULTS： After treatment， SBP， DBP and TCM symptom score of observation group were significantly lower than before； those indexes after 4 weeks of treatment were significantly lower than those after 2 weeks after treatment； the observation group B was significantly lower than the observation group A， with statistical significance （P＜0.05）. The repetitiveness and resolution ratio of protein differentiation expression point in observation group B were significantly better than in observation group A after treatment. The expression of 15 protein points in observation group down-regulated before treatment， and up-regulated after treatment to different extents； the observation group B was closer to control group， compared to observation group A. The expression of 6 protein points up-regulated， and then down-regulated to different extent after treatment； the observation group B  was closer to control group， compared to observation group A. A total of 11 protein points were identified. There was no statistical significance in the incidence of ADR between observation group A and observation group B （P＞0.05）. CONCLUSIONS： G. biloba extract combined with olmesartan medoxomil greatly influences the expression of serum protein in patients with essential hypertension and shows good antihypertensive and pressure-control effects with good safety.