Acute lung injury (ALI)/ acute respiratory distress syndrome (ARDS) is a common cause of respiratory failure in critically ill patients.ARDS occurs in about 10% of patients in intensive care units worldwide.Although the current situation has improved, there is still a lack of clear and effective treatments, and mortality and morbidity of ARDS are still as high as 30%-40%.ALI/ARDS is an acute inflammatory process caused by inflammatory cell infiltration leading to severe alveolar epithelial and alveolar capillary membrane damage, increased vascular permeability, pulmonary interstitial/alveolar edema.The pathophysiology of ARDS involves a variety of mechanisms including inflammatory cell infiltration, oxidative stress, alveolar capillary barrier disruption/permeability changes, apoptosis and tissue fibrosis, and activation of various molecular signal pathways including MAPK, NF-κB, AMPK/SIRT1, PI3K/Akt, Nrf2/HO-1, Fas/FasL, Wnt/β-catenin and Notch.This article reviews the research progress of molecular mechanisms related to the occurrence, development and treatment of ALI, in order to provide a certain reference for subsequent clinical and basic researches.