Abstract: Guidelines for the diagnosis and treatment of severe acute pancreatitis were published by the Pancreatic Surgery Group of Surgery Branch of Chinese Medical Association in 2007, and had great impact on the domestic standardized treatment and the improvement of efficacy of acute pancreatitis (AP). Since then, tremendous progress has been achieved in the research of AP, which influenced many important aspects of the management of AP. Therefore, it is necessary to revise the guideline. The revised guideline is renamed as Guidelines for the diagnosis and treatment of acute pancreatitis 〖STBX〗(2014 edition). 〖STBZ〗Diagnosis of acute pancreatitis is based on clinical features, plasma concentrations of pancreatic enzymes and results of computed tomography (CT). Modified CT severity index (MCTSI) is used in the severity assessment of the inflammation and necrosis of AP. AP can be subdivided into interstitial oedematous pancreatitis and necrotizing pancreatitis according to the pathological characteristics. The severity of AP is classified as mild acute pancreatitis (MAP), moderately severe acute pancreatitis (MSAP) and severe acute pancreatitis (SAP). The definition of SAP or MSAP depends on the duration of organ failure, which is transient (≤48 h) in MSAP but is persistent (>48 h) in SAP. Modified Marshall Scoring System is used in the assessment of organ failure. The dynamic disease process could be divided into 3 phases. Early stage (acute phase) usually lasts for 2 weeks, and is characterized by systemic inflammatory response syndromes (SIRS) and organ failure, which is the first peak of mortality. Middle stage (successional phase) has a peripancreatic fluid collection or necrotic collection as the major characteristics from the second week to the fourth week. Late stage (infection phase) is characterized by infection of pancreas and peripancreatic necrotic tissues after the fourth week, and is the second peak of mortality. Acute peripancreatic fluid collection (APFC), acute necrotic collection (ANC), walledoff necrosis (WON) together with pancreatic pseudocyst are the local complications. For acute biliary pancreatitis, choledochotomy or common bile duct exploration should be performed when the condition is stable in the MAP patients, but in the late period or during the necrosectomy in the MSAP and SAP patients. The important nonsurgical treatment in the early stage is fluid resuscitation and the organ function protection. The MSAP and SAP patients should be treated by enteral nutrition therapy when the intestinal function is recovered. For some susceptible patients, antibiotics should be used selectively. Treatments of acute compartment syndrome (ACS) include gastrointestinal decompression and catharsis, analgesia and sedation, using of muscle relaxant, bedside hemofiltration to reduce the tissue edema, relieving abdominal pressure by B ultrasound or CTguided percutaneous catheter drainage (PCD) of abdominal cavity and retroperitoneum. The indications for surgical treatment are infected necrosis and oppression symptoms. Surgery should not be done in sterile necrosis patients without symptoms. Surgical treatment should follow the delayed principle. In patients with infected necrosis, antibiotics and PCD could be the first choice of treatment. Surgical interventions of infected pancreatic necrosis include PCD, endoscopic, minimally invasive surgery (such as small incision surgery, videoassisted surgery) and open surgery (necrosectomy and drainage by the abdominal or retroperitoneal approach). The infected pancreatic necrosis is complex and diverse, rational surgical procedures should be selected separately or jointly according to the conditions in individual cases.