BACKGROUND/AIMS Severe acute pancreatitis (SAP)-associated liver injury is systematically one of main pathophysiological events due to SAP development. The aim of the study was to investigate whether fgl2 prothrombinase is involved in SAP-associated liver injury. METHODOLOGY Microthrombosis in the liver of rats with SAP was observed by Masson staining. Fgl2 prothrombinase expression in the liver of rats with SAP was analyzed by real-time PCR and immunohistochemistry methods. RESULTS Fgl2 prothrombinase gene and protein expression in SAP group were significantly up-regulated compared to sham-operation (SO) group. Immunohistochemistry staining showed that fgl2 prothrombinase was localized speci?cally to the endothelial cells of intrahepatic veins and hepatic sinusoids. Furthermore, Masson staining demonstrated that the proportion of hepatic microthrombotic capillaries in SAP group were evidently increasing in comparison to SO group and closely correlated with fgl2 expression (r=0.948, p