OBJECTIVE: To evaluate the effect of songlingxuemaikang(松龄血脉康, SLXMK) on mild essential hypertension in patients in terms of endothelial function.METHODS: We enrolled 90 patients with mild essential hypertension in Xuanwu Hospital from January 2016 to December 2016. To evaluate the effects of SLXMK, the 90 patients were randomly assigned at a 2∶1 ratio into 2 groups: the SLXMK group(500 mg per capsule, 4500 mg/d, n = 60) and the losartan potassium group(50 mg per table, 50 mg/d, n = 30). The total study period was 12 weeks,and the changes of blood pressure, laboratory test and endothelium function were compared between two groups.RESULTS: After 12 weeks of treatment with SLXMK,blood pressure(BP) and plasma lipid levels significantly improved(P < 0.05). Meanwhile, the reactive hyperemia index(RHI) increased in the SLXMK group(P < 0.05). The results of multivariate logisticregression analyses examining the association of selected variables with showed that high level of oxidized low density lipoprotein(ox-LDL) was positively associated with endothelial dysfunction.CONCLUSION: SLXMK not only effectively decreased BP and plasma lipid levels, but also reduced ox-LDL and RHI in patients with mild essential hypertension. And SLXMK might improve endothelial function through decreasing the circulating ox-LDL.