Objective:To observe the clinical efficacy of “Tianma Gouteng Granules” and its effect on vascular function in treating patients with primary hypertension  Methods:One hundred and seven cases with primary hypertension were randomized into control group (n=53) and observation group (n=54). The control group was treated with Nifedipine controlled-release Tablets orally, and observation group was treated with “Tianma Gouteng Granules” additionally, with the course of 3 months. The clinical efficacy and contents of FMD, CIMT, SOD, ET and MDA were observed  Results:①The total effective rate was 94.4% in the observation group and 81.1% in the control group, the clinical efficacy of the treatment group was superior to that of the control group (P<0.05). ② After treatment, the FMD was increased in both two groups (P<0.05), the observation group was higher than that of the controls (P<0.05); but IMT was decreased in both groups (P<0.05), and the observation group was lower than that of the controls (P<0.05). ③After treatment, the SOD was increased in both two groups (P<0.05), and observation group was higher than the controls (P<0.05); levels of ET and MDA in both groups were decreased (P<0.05), and the observation group was lower than that of the control group (P<0.05)  Conclusion:“Tianma Gouteng Granules” is effective to improve the clinical efficacy, improve vascular function and antioxidant activity in patients with primary hypertension.