The aim of the experiments was to investigate the effect of Semen Cuscutae aqua-acupuncture at the meridian point BL 20(脾兪) and BL 23(賢兪) on the blood pressure, plasma renin activity, plasma levels of aldosterone and atrial natriuretic peptide (ANP) in spontaneously hypertensive rats (SHR). The results of this study were as follows: 1. Systolic blood pressure was decreased significantly after Semen Cuscutae aqua-acupuncture at the meridian point BL 20, BL 23. 2. Plasma renin activity was increased significantly after Semen Cuscutae aqua-acupuncture at meridian point BL 23, BL 20. 3. Plasma levels of aldosterone was increased significantly after Semen Cuscutae aqua-acupuncture at the meridian point BL 20. 4. Plasma levels of atrial natriuretic peptide (ANP) was increased significantly after Semen Cuscutae aqua-acupuncture at the meridian point BL 23, but it was decreased significantly after Semen Cuscutae aqua-acupuncture at the meridian point BL 20. These results suggest that the changes of the depressor response after Semen Cuscutae aqua-acupuncture at the meridian point BL 20, BL 23 are related to the changes of the plasma renin activity, plasma levels of atrial natriuretic peptide (ANP) and aldosterone.