Objective : This study was done to investigate the effect of Gamioknyeo-jeon (GOJ) on spontaneously hypertensive rats. Methods : Spontaneously hypertensive rats were sensitized and challenged with GOJ for 4 weeks. the experimental group was treated with 56.7mg/kg/day of GOJ orally while the control group was treated with 56.7mg/kg/day of normal saline instead. Results : 1. GOJ significantly showed safety against cytotoxicity and toxicity in the liver. 2. GOJ significantly decreased the heart rate and the blood pressure in Spontaneously hypertensive rats. 3. GOJ significantly decreased the levels of aldosterone in Spontaneously hypertensive rats. 4. GOJ significantly decreased the levels of dopamine and norepinephrine in Spontaneously hypertensive rats. 5. GOJ significantly decreased the levels of potassium and chloride in Spontaneously hypertensive rats. 6. GOJ significantly decreased the levels of uric acid, BUN and creatinine in Spontaneously hypertensive rats. Conclusion : These results suggest that GOJ might be useful in treatment of hypertension.