Abstract: ［Abstract］Objective　To investigate and compare the effects of sevoflurane and propofol on one lung ventilation （OLV） induced ischemia-reperfusion injury. Methods Thirty-six patients undergoing thoracic surgery with OLV were randomized in two groups: sevoflurane group（Group S，n = 18 ）and propofol group（ Group P，n = 18）. Anesthesia was inducted with thiopental and was maintained with 1-2.5% of sevoflurane within the 40/60% of O2/N2O mixture in Group S. In Group P，anesthesia was inducted with propofol and was maintained with infusion of propofol and remifentanil. Hemodynamic parameters were monitored and blood samples were obtained before anesthesia induction（T 1）， 1 min before two lung ventilation（T 2），30 min after two lung ventilation（T 3）， and postoperative sixth hours（T 4）. Blood samples for the blood gas，ischemia-modified albumin（IMA），and malonyldialdehyde（MDA）were mensurated .Results Heart rate at T 2 and T3 in Group P was lower than that in Group S，but there was no difference（P＞0.05）.While there was no significant difference in terms of pCO2 and pH（P ＞0.05）.pO2 at T2 and T3 in Group S was significantly lower than that in Group P（P <0.05）. IMA levels and MDA contents at T 4 in Group S were significantly lower than those in Group P（P <0.05）. Conclusion　Sevoflurane may offer protection against ischemia-reperfusion injury after OLV in thoracic surgery.