ObjectiveTo determine the characters of symptomatic pancreatic pseudocyst due to acute pancreatitis and effects of surgical treatment with two kinds of procedure （internal drainage or external drainage）. MethodsOne hundred and fifteen cases hospitalized during recent ten years were retrospectively analyzed.ResultsWe found that necrotic tissue existed in the pseudocyst in most cases and infection might occur in these pseudocyst. Although effect of two kinds of surgery was similar, the clinical course was different. The complications after surgery were fewer in patients underwent internal drainage than that with procedure of external drainage, and average hospital day was 7d in cases with internal drainage and 11d in cases with external one respectively. Surgery of internal drainage used in treatment was not only successful in noninfectious and single pseudocyst, but in infectious or multiple seudocyst.ConclusionInternal drainage should be used in most cases and considered as the first selection in surgery of pseudocyst due to acute pancreatitis.