Background　In epithelial tight junctions， Claudins are considered as key integral protein regulators responsible for the maintenance of alveolar epithelial barrier integrity. Disruption of the paracellular alveolar permeability barriers is a significant pathologic consequence of acute lung injury.　Objective　To explore relations of claudins with acute lung injury.　Content　This review is focused on the expression of claudins during acute lung injury.　Trend　Claudins may be potential markers for acute lung injury induced by hemorrhagic shock.