Objective To describe the hemodynamic characteristics of normal pancreas and pancreatic tumors by 64 slices helical CT perfusion imaging, to evaluate the role of CT perfusion in the diagnosis of pancreatic tumors. Methods Perfusion CT scan was performed in 149 patients, including 36 patients with normal pancreas, 105 patients with pancreatic tumors and 8 patients with duodenal papillary carcinoma. The parameters including blood flow (BF) ,blood volume (BV) and permeability surface area product (PS) were measured. Results The mean value of BF, BV and PS of normal pancreas were (135.24±48.36) ml· min-1·kg-1, (200.55±54.96)ml/kg and (49.75±24.27) ml·min-1·kg-1, respectively. Pancreatic carcinoma has a lower BF, BV and PS,whieh were 31.77±19.36 ml·min-1· kg-1, (66.84±39.49)ml/kg and (37.64±27.14) ml·min-1·kg-1, respectively. The aforementioned parameters in pancreatic cysts were close to zero. The parameters in pancreatic carcinoma were significantly lower than those in normal pancreas(P<0.05); the BF and BV in duodenal papillary carcinoma were significantly lower than those in normal pancreas(P<0.05), while the value of PS was not significantly different from that in normal pancreas; the aforementioned parameters in pancreatic cysts were significantly different from those in normal pancreas(P <0.01). Conclusions In perfu sion CT, normal pancreas was an organ with symmetrical BF,BV and PS. Pancreatic carcinoma was a tumor with low perfusion and decreased PS. Duodenal papillary carcinoma had decreased BF and BV with no significant change in PS. Pancreatic cyst had no blood perfusion. The 64 slice helical CT peffusion imaging was invaluable in differential diagnosis of pancreatic tumors.