Among many pancreatic diseases, chronic pancreatitis is an area that cannot be ignored, and the data show that its incidence is gradually increasing. Chronic pancreatitis refers to recurrent or persistent inflammatory lesions of the pancreatic parenchyma, with extensive fibrosis, focal necrosis and stone formation in the pancreatic duct or diffuse calcification, which can cause atrophy or loss of pancreatic vesicles and islet cells, often with the formation of pseudocysts. Due to the unclear etiology, prolonged course of the disease, variable clinical manifestations and difficulties in early diagnosis, the treatment effect is not very satisfactory. To date, chronic pancreatitis is still a type of pancreatic disease that affects people’s quality of life, and its treatment is still a challenging topic. The etiology of chronic pancreatitis is influenced by various factors such as country, region, geographical environment, living habits and economic status, and its etiology has not been fully elucidated yet. (1) reported that 52% of the causes of chronic pancreatitis are alcoholic, 28% are idiopathic, 13% are pancreatic schizophrenia, and 7% are familial or hereditary (caused by gene mutations. (2) Most foreign data show that heavy alcohol consumption is the main causative factor of chronic pancreatitis, accounting for about 70% of all causes. Recent reports, chronic pancreatitis 65.4% of the disease because of alcohol, and the average alcohol intake of about 75.0g / d. (3) At present, China lacks epidemiological data on the incidence of chronic pancreatitis and the causative factors, in recent years there is a trend of increasing reports of chronic pancreatitis, the causative factors are more clearly biliary in the majority, accounting for about 47.0% – 64.5%. (4) The main biliary diseases causing chronic pancreatitis are acute and chronic cholecystitis, cholelithiasis, cholangitis, spasm or dysfunction of the sphincter of Oddi, etc. Other etiologies reported in the literature include high protein and high fat diet, hyperlipidemia, malnutrition, pancreatic injury, duodenal obstruction, etc. Second, the mechanism of pancreatic enzymes in the treatment of chronic pancreatitis The aims of treatment of chronic pancreatitis (5): (1) to stop the disease process and prevent complications; (2) to correct the deficiency of exocrine function; and (3) to relieve pain. Pancreatic exocrine insufficiency and pain are the main manifestations of chronic pancreatitis. Application of pancreatic enzyme preparation not only has the ability to improve the symptoms of diarrhea and abdominal distension caused by pancreatic exocrine insufficiency, but also has an important role in relieving pancreatic pain. Existing studies suggest that the mechanism of pain in chronic pancreatitis is multifactorial and may be related to the following factors: (1) increased pressure in the pancreatic duct; (2) inflammation involving the pancreas, peripancreatic peritoneum and nerves; recurrent pancreatic auto-digestive necrosis; and (4) increased pressure due to complications such as pseudocysts or duodenal obstruction. Therefore, pancreatic enzyme supplementation is used for pain relief in response to the existing pathological mechanisms. The mechanism may be the presence of a negative feedback mechanism in which pancreatic enzymes in the intestinal lumen inhibit pancreatic juice secretion. Under normal conditions, cholecystokinin-releasing peptide (CCK-RP) in the duodenum is denatured by pancreatic enzymes. In chronic pancreatitis, the release of pancreatic enzymes decreases, resulting in insufficient denaturation of CCK-RP and increased release of CCK, which in turn leads to increased pancreatic fluid secretion resulting in elevated pancreatic ductal pressure and pancreatogenic pain. The application of pancreatic enzyme preparations leads to adequate denaturation of CCK-RP and therefore reduces CCK release. Many clinical studies have confirmed that exogenous pancreatic enzyme preparations have led to pain relief in many patients with chronic pancreatitis. Third, the factors affecting the in vivo effect of pancreatic enzyme preparations Pancreatic enzymes are physiologically active complex enzymes, which are recognized as one of the biochemical drugs with precise efficacy in the international health care community. It mainly contains trypsin, chymotrypsin, pancreatic amylase and pancreatic lipase, as well as carboxypeptidase, ribonuclease, elastase and kinin release enzyme. The significance of pancreatic enzyme replacement therapy is to compensate for the lack of pancreatic enzymes, correct pancreatic insufficiency and relieve pain, and improve the quality of life. However, oral pancreatic enzymes are affected by gastric acidity, duodenal acidity, the size of pancreatic enzyme particles and the interaction between pancreatic enzymes, and different dosage forms have their own advantages and disadvantages. (1) Gastric acid and duodenal acidity When the pH in the stomach is ≤4, lipase is denatured and inactivated; when the duodenal pH is ≥6, pancreatic enzyme is activated after several minutes. Compared with lipase, protease has stronger tolerance to gastric acid. Meanwhile, the acidic duodenal fluid stimulates the secretion of large amount of bile and pancreatic juice, which dilutes the intestinal contents and reduces the concentration of pancreatic enzyme. Therefore, the optimal pH for pancreatic enzyme to maintain its activity should be greater than 6.0. When pH < 4.0, lipase is inactivated.