Fifty three patients with acute necrotizing pancreatitis were performed operation, treated surgically, including incision of the pancreatic capsule to release the pancreatic presure, removal of necrotic tissue, and placement of drainage tube around pancreas. Twenty two patients (41.5%) developed postoperative peripancreatic abscess. The average hospitalized days (83.3±25.1 days) of the patients with peripancreatic abscess was longer than those without (22.7±14.7 days) peripancreatic abscess (Ｐ＜0.01). Six cases of 28 (21.4%) patients who had localized or scattered pancreatic necrosis developed peripancreatic abscess, 16 cases of 25 (64.0%) patients who had subtotal or total pancreatic necrosis developed peripancreatic abscess which showed significant difference between two groups (Ｐ＜0.01). Among 21 patients in whom 2 to 4 doublelumened tubes for negative presure drainage were placed,5 cases (23.8%) had peripancreatic abscess but 32 patients with only one tube placed, 17 patients (53.1%) had peripancreatic abscess, the difference between two groups were significant (Ｐ＜0.05). At least 6 patients whose drainage tubes worked badly produced postoperative peripancreatic abscess. These results indicate that the peripancreatic abscess is closely related with the severity of the disease, surgical treatment, and proper postoperative care of the drainage tubes.