The new experimental model has been set as a standard with the purpose to explore and analyze the role of phospholipase A2 in predicting the severity of acute pancreatitis with specific interest for the onset of hemorrhagic necrotizing pancreatitis and pleuropulmonary complications. The experiments were performed on dogs (n = 25), and acute pancreatitis was induced with the injection of 10% sodium-taurocholate into pancreatic duct. Four experimental groups of animals were formed, so that 2 groups had lymph held by draining the thoracic duct. In the other two groups, the lymph had been put into system circulation, so that the nylon bag was set around the pancreas in order to prevent pancreatic juice to be spilt into abdominal cavity. The analyses of the levels of amylase, lipase, pancreatic amylase and phospholipase A2 in of serum, lymph and exudate were performed. The positive correlation was found between increased concentration of phospholipase A2 in serum and reduction of partial pressure of oxygen and pH of blood and the degree of severity of respiratory failure. The speed and intensity of development of the acute hemorrhagic necrotizing pancreatitis, as well as the severity of pulmonary complications might be estimated upon the of increase of the levels of phospholipase A2 in serum and lymph. This experimental model enables the studying of pathogenesis of acute pancreatitis and systemic complications.