【Abstract】Objective To establish rats with SAP model at high altitude area by animal experiments in the case of zero intervention and observe the expression of TNFα in damaged liver at different times. This study aim to clarify the relationship between hepatic lesion and the expression of TNFα from the perspective of cytokines in high altitude hypoxia. This study would provide the basis for the mechanism study of diagnosis and treatment of severe acute pancreatitis.Methods The rats with SAP model was established by sodium taurocholate retrograde injection. The content of the ALT and AST in serum will be measured by centrifugation. The tissue microarray was made by the method of Immunohistochemistry. The content of TNFα in liver was measured. The content of the ALT, AST of SAP rat were measured in different altitude. The correlation between the expression of TNFα and altitude will be verified. Results The expression of ALT, AST and TNFαincreased with time in the same altitude after the rat hepatic lesion. The expression of ALT, AST and TNFαincreased with altitude at the same time after the rat hepatic lesion but the control group.Conclusion The hepatic lesion of SAP rat aggravated with time and the hepatic lesion of SAP rat aggravated with altitude. The expression of TNFα in SAP rat increased with time and the expression of TNFα in SAP rat increased with altitude