Authors compared early phase scan of the IV bolus CT (two phase incremental bolus dynamic CT) with late enhanecd scan similar to the conventional contrast enhanced CT for evaluation of the advantages of the IV bolus CT with two viewpoints of the pancreatic or peripancreatic mass and peripancreatic lymphadenopathy in 68 patients-28 cases of the pancreatic cancer, 6 cases of the pancreatitis and 34 cases of the pancreatic or peripancreatic metastasis. On the diagnosis of the pancreatic or peripancreatic mass, IV bolus CT could show the lesion(s) more easily in 41% (Grade II; 13/31) and much more easily in 34% (Grade III; 10/31) when compared with conventional contrast CT scan. The diagnosis of the peripancreatic lymph node involvement was also easy in 51%(Grade II; 20/39) and much easier in 37% (Grade III; 14/39). We thought that these differences were originated from the increase of the contrast between the lesion and normal portion because the early enhanced scans reflected the active blood flow change more exactly. Therefore IV bolus CT had advantages in comparison with the conventional drip infusion contrast CT in the diagnosis of the presence and pathologic extension of the pancreatic and peripancreatic lesion.