Objective To study the pathological changes of acute hemorrhagic necrotizing pancreatitis(AHNP) complicated with acute lung injury(ALI). Method The model of AHNP with ALI was established in rats. The changes of function and structure of pancreas and lung were observed. Results One hour after induction of the model , pancreas showed mild edema and congestion . 12 hours after introduction of the model , the typical pathological changs of AHNP were found . The lung extravascular water volume and levels of PaCO 2 increased significantly, and the PaCO 2 decreased obviously. Morphological examination demonstrated that inflammatory cell , insterstitial edema , intra-alveolar hemorrhage ,desquamate and disintegration occurred in the lungs. Conclusions The pancreatic and pulmonary morphologic changes in this model is similar to the changes in clinical AHNP with ALI , which suggests that the model can be used to study the mechanism of AHNP with ALI and evaluate the effect of drugs for AHNP with ALI.