Abstract: Objective To evaluate the effects of edaravone precondi- tioning on high-mobility group box 1 in patients with one lung venti-lation. Methods Fifty ASA physical status Ⅰ～Ⅱ patients of both sexes ，aged 66—75 yr from January 2016 to January 2017 at Affiliated Hospital of Xuzhou Medical University，undergoing elective OLV, were randomly divid ed into two groups (n=25 each) : control group (saline group) and observation group (edaravone preconditioning group). In observation group edaravone 5mg/kg was infused intravenously for 30 min， while in control group the equal volume of normalsaline was given instead.Edaravone b efore injection（T1）、at 3h of OLV（T2）、at 24h of OLV（T3）、at 48h after operation （T4）,venous blood samples were obtained for determination of the serum high-mobility group box 1 were recorded , SaO2 too.Before OLV （T1）、at 3h of OLV（T2）Pmean、Ppeak、PETCO2 were recorded.The number of ALI/ARDS at 48h after operation were recorded. Results HMGB1 of two groups at T2-4 were higher than the same group T 1, SaO2 was lower;The HMG B1 and SaO 2 of group B were higher than group A at T 2-4 （ P＜0.05）; The Ppean、Ppeak、 PETCO2 of two groups at T2 were higher than the same group at T1; The Ppean、Ppeak、 PETCO2 of group B were lower than group A at T 2（P＞0.05）; Incidence of ALI/ARDS of group B were lower than group A at 48h after operation . Conclusio n Edaravone may reduce lung injury by reduced expression of HMGB1 on the pulmonary function