Abstract: Objective To evaluate the value of several Computed Tomograph (CT) scoring systems in predicting the development of acute pancreatic pseudocyst (PPC) in severe acute pancreatitis (SAP) during early stage. Methods One hundred and sixty-two patients with SAP were retrospectively observed and subjected to clinical, laboratory, and radiology investigation from October 2007 to December 2010. Three different CT scoring systems including CT severity index (CTSI), Modified CT severity index (MCTSI) and Extrapancreatic Inflammation on CT score (EPIC), were used for the determine of PPC, while the predictive values of these three CT scoring systems in the presence of PPC were analyzed by the ROC curve. Results Forty-eight patients (29.6%) were observed the formation of PPC. The scores of CTSI, MCTSI, EPIC and the occurrence rate of ascites in PPC group were significantly higher than those in non-PPC group with One-way ANOVA analysis. Among the three CT scoring systems,EPIC score showed a larger area under ROC curve (AUC=0.914) than CTSI (AUC=0.674) and MCTSI (AUC=0.72) did. Conclusion EPIC scoring system has better prediction of PPC in SAP patients than CTSI and MCTSI.