Objective： To establish an acute lung injury model by seawater aspiration in rats. Methods： Twenty-four rats were randomly allocated into 2 groups： control group （n= 9） and model group （n= 15）. The acute lung injury model was established in rats by aspirating 2 ml seawater/kg body weight after 9-10 seconds of breath occlusion. The aspiration was repeated by the same means 2 rain later. Rats in control group aspirated no seawater. Arterial blood gases and respiratory rates were observed before aspiration and 10 min, 30 rain, 1 h, 2 h and 4 h after aspiration. The survival times of animal were also recorded. The rats were sacrificed 4 h after aspiration; the lung index, total protein （TP） contents, white blood cell （WBC） count in bronchoalveolar lavage fluid （BALF）, and the pulmonary histopathology were observed. Results： Compared with control group, model group had a significantly increased respiratory rate and a decreased PaO2 （P〈0.05）,which subsequently rose again and remained at a lower level. The model group also had a markedly increased lung index, TP contents and WBC counts （P〈 0.05）. Obvious edema, alveolar atrophy and inflammatory infiltration were found in model rats. Conclusion： An acute lung injury model by seawater aspiration has been successfuly established