This study sought to determine the effect of the haemorrheological changes on the pathological damage to pancreas in acute pancreatitis. 96 Wistar rats, four months old, were allocated into three groups: group I (n = 32) received surgery for pancreatic duct obstruction (PDO) with secretion stimulation; group II (n = 32) for PDO with high molecular dextran (DX110) injection intravenously, and group III (n = 32) for PDO with secretion stimulation and DX110 injection intravenously. Ten other rats were used as controls (group IV) for laparotomy alone. The results showed that PDO with hypersecretion could induced edematous pancreastitis and PDO with DX110 injection induced only very lightly oedema in the pancreas which was similar to the result of PDO alone, although the haemorrheological changes were obvious in these rats. PDO with hypersecretion and DX110 injection induced acute necrotic pancreatitis, and the pathological lesion in the pancrease which changed gradually from edematous to necrotic could be observed. This result suggests that haemorrheological change may not be a causative factor of the acute necrotic pancreatitis, but it probably could exacerbate the damage to pancreas in acute pancreatitis and play an important role in the transformation from edematous to necrotic pancreatitis.