Objective : This study was done to investigate the effect of KJT on hypertension. Methods : Spontaneous Hypertensive Rats were sensitized and challenged with Kamijaeumganghwatang(KJT) for 5 weeks. Experimental group was treated with $200mg/day/2m{ell}$ of KJT orally and control group was treated with $2m{ell}/day$ of normal saline instead. Results : 1. KJT significantly showed significant protection against cytotoxicity and toxicity in the liver and the kidney. 2. KJT significantly decreased the blood pressure in SHR. 3. KJT significantly decreased the levels of aldosterone in SHR. 4. KJT significantly decreased the levels of dopamine, norepinephrine and epinephrine in SHR. 5. KJT significantly decreased the levels of sodium and potassium in SHR, but it did not decrease the levels of chloride in SHR. Levels of calcium in SHR increased, but only insignificantly. 6. KJT significantly decreased the levels of IL-6 in SHR, and significantly increased the levels of IL-10 in SHR. 7. For histological effects, KJT dillated capillary vessels in the kidney, significantly decreased eosinophilic changes in heart cells, and significantly decreased endothelial damage in the aorta. Conclusion: These results suggest that KJT is useful in treatment of hypertension.