Abstract: Twenty four patients with essential hypertension（EH）were treated for two weeks with capoten（group C 12 cases）or nifedipine（groLip N 12 cases）.The results showed that that before treatment,the plasmalevels of endothelin（ET）,renin activity（PRA）,angiotensin Ⅱ（AT Ⅱ）and aldosterone（ALD）in patientswith EH were signiflcantly higher than those in normal ctintrols（P＜001 and P＞0. 05）,after treatment,the level,of AT Ⅱ,ALD and mBP and mHR in group C decreased significantly（P＜0.01 and P＜0.05）ascompared with pre-treatment,but the plasma levels of FT and PRA had no significant difference（P＜0.05）.After treatment the levels of ET and mBP in group N were lower than before treatment（P＜0.01.respective-ly）;the plasma levels of AT and ALD decreased slightly,without significant difference as compared with be-fore treatment（P＞0.05）;mHR increased significantly than hefore treatment（P＜0.01）.It suggests thatthese two drugs are capable of different hypotensive mechanisms,and they may play a better role if used to-gether.