Objective:To observe the levels of serum endothelin(ET),nitric oxide(NO),tumor necrosis factor-α(TNF-α)and interleukin-6(IL-6)in prehypertension and hypertension patients.Methods:Three groups were recruited from 3050 subjects of regular health checkup in Tangshan Railway Hospital from June to September,2007. Prehypertension (PH) group: n=106,Essential hypertension (EH) group: n=91,and Normotensive (NT) control group: n=98.The levels of ET,TNF-α,IL-6 and NO were compared by radioimmunoassay and biochemical tests. Results: ①Compared with NT group,body mass index (BMI) and serum lipids (TC,TG,LDL-C) were significantly increased in PH and EH groups (P<0.05),high-density lipoprotein cholesterol (HDL-C)was decreased in EH groups (1.59±0.15 vs. 1.77±0.19,P<0.05). ②Compared with NT group,ET,IL-6,TNF-α were increased in PH and EH groups (P<0.05).NO was increased in PH group (6.55±0.94 vs. 5.87±0.80,P<0.05) while decreased in EH group (5.28±0.81 vs. 5.87±0.80,P<0.05). ③Logistic analysis indicated that BMI,ET,NO,TNF-α and IL-6 were related to the hypertension. Conclusion: ET,NO,TNF-α,IL-6 were elevated in prehypertension patients and those might be used to predict the risk of hypertension.