Inclusion Criteria:  Obtention of a written informed consent According to Revised Atlanta Classification, abdominal CT/MRI and EUS were diagnosed as WON The diameter of WON ≥6cm Patient capable of fill in the quality of life questionnaire The distance between the EUS-probe and WON was < 1 cm.  Exclusion Criteria:  No written informed consent pancreatic cystic tumor, pancreatic cancer and other benign and malignant tumors pancreatic pseudocyst WON too far from the stomach and duodenum to perform endoscopic drainage Serious abnormalities in liver and kidney function and coagulation function Pregnant, parturient or breastfeeding women