Engraftment with expulmonary adult stem cells has great potential for treatment of acute lung injury (ALI).The engrafted adult expulmonary stem cells can migrate to the injured lung tissue guided by a series of signal factors released by injured pulmonary tissue cells.Stem cells localized in the injured lung tissue and inflammatory area can differentiate into lung tissue cells (including lung epithelial cells and pulmonary vascular endothelial cells) and exert their functions.The engrafted expulmonary adult stem cells are not only capable of differentiation,but also have antiinflammatory effect and immunomodulatory effect,making the related area a focus of study.