Abstract： Objective To establish animal model of acute lung injury(ALI)induced by seawater infusion following open chest trauma in dogs to study the mechanism and the therapic methods.Methods Twelve-health-hybridis dogs were randomly divided into two groups:pneumothorax group and model group,each group for 6 dogs.The parameters of breathing rate,arterial blood gas,hemodynamics,cytokines of plasma and the bronchoalveolar lavage fluid(BALF),the microvascular permeability and histological appearance of pulmonary were recorded and compared between both groups.Results After injuried for 6 hours,compared with pneumothorax group,the values of arterial oxygen partial pressure(PaO2),oxygenation index(PaO2/FiO2),which was smaller than 300,significantly decreased in model group,and the values of MAP,CO as well as D/W dropped obviously too,whereas the levels of electrolytes,osmotic pressure,mediators of inflammation in plasma,TNF-α in BALF and moisture in lung increased obviously.In model group lung histopathological changes were found obviously,whose item alteration conformed to ALl pathological changes.Conclusions Seawater infusion following open chest trauma can induce ALI in dogs,and the animal model may be established successfully,which has itself unique characteristic.This provide foundation for further study of therapy of ALI induced by sea water infusion following open chest trauma.