In present study, the levels of Nrf2 (nucleus), HO-1 and NQO1 increased significantly, while the level of Keap-1 and Nrf2 (cytosol) reduced significantly, indicating that the mechanism of the hepatopretective effect of cos against ALI may be achieved via the Nrf2 signaling pathway. The gene discussed is HMOX1; the disease is acute respiratory distress syndrome.