Objective To discuss the value of combining the physiological and operative severity score for enumeration of mortality and morbidity(POSSUM)and acute physiology and chronic health evaluation Ⅱ(APACHE Ⅱ)in severe acute pancreatitis(sAP).Methods 60 cases of SAP were divided into surgery group(n=15)and non-surgical group(n=45),Non-surgical group was vahde with APACHE Ⅱ score,the surgery group with POSSUM score,decided to continue conservative treatment or surgery treatment,Observation of two ways with the complications and death.Results The rates of compHcafions and death were(0.37±0.08)and(0.27±0.09)in Single-operation group(n=15)higher than(0.76±0.14)and(0.61±0.15)in surgical group(n=11)(t1=3.125,t2=3.211,P＜0.01);APACHEⅡ score of mortality in operation group and non-surgical group were no significant difference(x2=2.28,x2=1.98,P＞0.05);APACHE Ⅱ score were(10.12±6.27)in survival group(n=46)were lower than (25.75±7.90)in death group(n=14)(t=2.525,P＜0.05.Conclusion The score of dynamic APACHE Ⅱ has better effect to judge the timing of surgery,and the score of POSSUM has high value to predict post-operative complications and deaths occurred in patients with severe acute pancreatitis.