Objective To explore the relationship between C reactive protein and the diagnosis of acute pancreatitis. Methods Colect 37 cases of acute pancreatitis in the past three years, including 24 cases of mild acute pancreatitis and 13 cases of severe acute pancreatitis. Determine the value of C reactive protein in different period. Compared with 37 cases of healthy people. At the same time, compared between the mild acute pancreatitis and the severe acute pancreatitis. Result There is significance in comparing between the acute pancreatitis and the healthy people. There is significance in different degrees of pancreatitis too. Conclusion C reactive protein is an important index for the diagnosis of acute pancreatitis and the standard for judging the severity of acute pancreatitis.