AIM: To investigate the effect of ginkgo biloba extract (EGb 761) on lung injury induced by intestinal ischemia/reperfusion ( Ⅱ/R).METHODS: The rat model of Ⅱ/R injury was produced by clamping the superior mesenteric artery for 60 min followed by reperfusion for 180 min. The rats were randomly allocated into sham, Ⅱ/R, and EGb +Ⅱ/R groups. In EGb + Ⅱ/R group, EGb 761 (100 mg/kg per day) was given via a gastric tube for 7 consecutive days prior to surgery. Rats in Ⅱ/R and sham groups were treated with equal volumes of the vehicle of EGb 761.Lung injury was assessed by light microscopy, wet-todry lung weight ratio (W/D) and pulmonary permeability index (PPI). The levels of malondialdehyde (MDA) and nitrite/nitrate (NO2-/NO3-), as well as the activities of superoxide dismutase (SOD) and myeloperoxidase (MPO)were examined. Western blot was used to determine the expression of inducible nitric oxide synthase (iNOS).RESULTS: EGb 761 markedly improved mean arterial pressure and attenuated lung injury, manifested by the improvement of histological changes and significant decreases of pulmonary W/D and PPI (P ＜ 0.05 or 0.01).Moreover, EGb 761 markedly increased SOD activity,reduced MDA levels and MPO activity, and suppressed NO generation accompanied by down-regulation of iNOS expression (P ＜ 0.05 or 0.01).CONCLUSION: The results indicate that EGb 761has a protective effect on lung injury induced by Ⅱ /R, which may be related to its antioxidant property and suppressions of neutrophil accumulation and iNOSinduced NO generation. EGb 761 seems to be an effective therapeutic agent for critically ill patients with respiratory failure related to Ⅱ/R.