Objective To observe the regulatory effects of Smilax glabra on blood pressure and vasoactive substances in renovascular hypertensive rats． Method Seventy healthy adult male rats were used to establish the model of renovascular hypertension by two-kidney two-clip procedure． Model rats were divided into model control group，high ( Smilax glabra 6 g / kg) ，moderate ( Smilax glabra 3 g / kg) ，low ( Smilax glabra 1. 5 g / kg) dose groups and the positive control group ( captopril 5 mg / kg) according to systolic blood pressure in the renal hypertensive rats． Rats of the drug groups were administrated the corresponding drugs by once daily for 4 weeks，and measured blood pressure once a week．After the last administration，the blood ANP，NO，ET，CGRP and Ang II of the rats were measured． Result Smilax glabra significantly reduced SBP，DBP and MBP in the renal hypertensive rats ( P ＜ 0. 05，P ＜ 0. 01 ) ，significantly reduced the ANP，ET levels ( P ＜ 0. 05，P ＜ 0. 01) ，and increased the NO level ( P ＜ 0. 05) ． Conclusion Smilax glabra has a blood pressure lowering effect and regulates the blood pressure by reduced ANP，ET，and increased NO levels．