Acute pancreatitis (AP) is an acute inflammatory disease of the pancreas which can lead to a systemic inflammatory response syndrome with significant morbidity and mortality in 20% of patients. Part of endocrine function of pancreas would be affected in AP. Stress hyperglycemia would explode at acute phase. There are two reasons. One is because that sympathetic hyperactivity makes glucagon elevated. Secondary, microcirculation disorder makes pancreas edema, ischemia and necrosis, affecting secretion and excretion of insulin. In severe acute pancreatitis, there may be ketoacidosis. Many scoring systems for predicting prognosis of severe acute pancreatitis also contains glucose values, such as the Ranson scoring system and the Glascow scoring system. On the other hand, Type 2 diabetes has become a global pandemic disease. Most of patients of type 2 diabetes are obese, who easily complicated gallstone disease and hypertriglyceridemia. All of above could be the risk factors for acute pancreatitis. Our initial small sample research also suggests undiagnosed diabetes patients whose glucose value elevated is significantly worse than the known diabetic patients. Therefore, the investigators believe that glucose directly affects the prognosis of AP. So the investigators decide to follow up and observe 1000 cases of patients with acute pancreatitis, determining of blood sugar, blood amylase, hemoglobin and glycosylated hemoglobin level. At last, using ROC curve method to identify the die cutting between blood glucose level and acute pancreatitis, and makes analysis of the diagnostic value.