Objective To explore the value of combination APACHE II, Ranson with BalthazarCT Scoring System predicting the prognosis of severe acute pancreatitis (SAP). Methods The relationship between APACHE II, Ranson, Balthazar CT scoring systems and mortality of severe acute pancreatitis (SAP) patients admitted to the intensive care unit (ICU) of West China Hospital from January 1st, 2007 to December 31st, 2008 was analyzed. Results There was statistical difference between high and low score groups in the APACHE II, Ranson, BalthazarCT scoring systems. Combination APACHE II, Ranson with Balthazar CT scoring system, there was statistical difference between high and low Balthazar CT score group both in APACHE II and Ranson scoring systems. Conclusion APACHE II, Ranson combined with Balthazar scoring systems can be used as a more important clinical reference in evaluating the diagnosis and prognosis of severe acute pancreatitis.