Objective:To observe the effect of the aqueous extract from Cyclocarya paliurus on hypertensive rats induced by L-NAME（Nω-nitro-L-arginine methyl ester hydrochloride）.Method: Hypertensive rats were given by L-NAME for 4 weeks to produce hypertensive model.The 40 hypertensive rats were randomly divided into model group

C.paliurus extract low

medium and high dose group（3.0

6.0

12.0 g·kg-1）

captopril group（0.010 g·kg-1）

additional 8 rats were choose as control group.Non-invasive blood pressure measurement was used to detect the arterial blood pressure of rat tail once a week for 6 weeks.The left ventricular weight index and kidney weight index were calculated

and morphological changes of the thoracic aorta were observed.Result: After 6 weeks of administration

the systolic and diastolic blood pressure of hypertensive rats significantly decreased（P<0.01

P<0.05）

in low

medium and high-dose groups

the decreased systolic blood pressure rate was 16.18%

16.92%

16.92%;the decreased diastolic blood pressure rate was 15.98%

15.73%

16.64%.The treatment groups decreased left ventricular thickening and kidney weighting

and could moderate medial membrane thickening of the thoracic aorta.Conclusion: C.paliurus extract could reduce blood pressure in L-NAME induced hypertensive rats.