Objective To evaluate the clinical significance of plasma endothelin (ET)and sera nitric oxide (NO) detection in patients with hypertension .Methods The level of plasma ET and sera NO in 47 cases hypertension patients were measured by RIA and colorimeteric method ,respectively .Results The level of ET in the patients was much higher (123.6±14 6pg/ml)than that of the control group(87.3±12.6pg/ml),and the level of NO was much lower (4.85±0.75umol/L)than that of the control group (5.76±0.64umol/L).The changes were correlated to the severity of the diseases .Conclusions These results suggest that plasma ET and sera NO may play a part in pathophysiologic process in hypertension ,and they might served as one of indexes to assess the severity of hypertension . [