Objective To investigate the effects of anesthesia on plasma level of endothelin(ET) and atrial natriuretic polypeptide (ANP) in patients undergoing upper abdominal surgery. Methods Thirty ASA Ⅰ -Ⅱ patients(14 male, 16 female), aged 31-68 years and weighing 41-82kg, undergoing elective upper abdominal surgery were divided into three groups with ten patients in each group: Ⅰ desflurane group,Ⅱ isoflurane group and Ⅲ propofol group. The patients were premedicated with intramuscular phenobarbital sodium O.1g and atropine 0.5mg. Anesthesia was induced with midazolam 0.lmg?kg-1, propofol 1 mg?kg-1, vecuronium .015mg?kg-1 and fentanyl 4?g?kg-1 . After intubation the patients were mechanically ventilated and PET CO2 was maintained with 1.0 MAC desflurane in group I or 1.0 MAC isoflurane in groupⅡ or propofol infusion at 60-70 ?g ?kg-1?min-1 in groupⅢ and vecuronium infusion at l-2?g?kg-1?min-1 . ECG, HR, BP, SpO2, PETCO2, end-tidal concentration of desflurane or isoflurane, tidal volume (VT), total compliance ( C?), Pplat, Ppeak were monitored during anesthesia. Blood samples were taken from peripheral vein before anesthesia(T1 ), after induction(T2), 10 min(T3), 50 min(T4) after skin incision and at the end of surgery(T5 ) for determination of plasma levels of ET and ANP by radioimmunoassay. Results (1) There was no significant difference in plasma levels of ET between group Ⅰ and Ⅱ , but ET level decreased significantly during isoflurane inhalation. (2) There was no significant change in plasma ANP level during anesthesia in group I but plasma ANP level decreased significantly at 50 min after skin incision in group Ⅱ and increased significantly at the end of operation in group Ⅲ . (3) MAP decreased significantly after induction in the three groups.Conclusions Anesthesia induced with propofol and maintained with isoflurane could be anesthesia of choice patients with airwayhyperreactivity in terms of plasma ET level which is a strong bronchial constrictor.