To observe the effect and mechanism of Hypertension Regulating and Collaterals Activating Prescription in the treatment of H-hypertension. Methods:A total of 94 patients with H-hypertension in March 2015 to February 2016, were divided into two groups by random number table method, 47 cases in each group, the control group was treated with blade, 1 piece/d; while the study group treated with blade + Hypertension Regulating and Collaterals Activating Prescription, once a day, treatment lasted for two courses. The effect, vascular active substances, blood rheology, oxidative stress indicators and renin-angiotensin Ⅱ-aldosterone system (RAAS) changes were observed. Results:1) After the treatment, the study group had significantly better results in symptoms score and total scores than the control group expect for shortness of breath, fatigue, forgetfulness (P<0.05); 2) After the treatment, the day and late systolic pressure, diastolic blood pressure and systolic blood pressure, diastolic blood pressure of the study group met a significantly greater drop than the control group (P<0.05); Hcy concentration had no statistical significance (P>0.05); 3) RA, Ang Ⅱ in the study group were significantly lower than the control group (P<0.05); 4) There were no statistically significant differences in MDA, MPO, SOD between two groups (P>0.05); 5) After treatment, PGI2 in the study group was lower than the control group， and TXA2 was higher, the differences were statistically significant (P<0.05); 6) platelet activating factors, platelet aggregation rate, whole blood viscosity, high shear in the study group were lower than that in the control group, the differences were statistically significant (P<0.05). Conclusion:Hypertension Regulating and Collaterals Activating Prescription can effectively control the blood pressure, and improve symptoms in the treatment of H-hypertension, which is worthy of clinical promotion. The mechanism may be related to regulating RAAS system, protecting endothelial cells and reducing blood viscosity.