Objective:To determine the effects of parenteral nutrition (PN) and enteral nutrition (EN) on biochemical and clinical outcomes in patients who underwent pancreaticoduodenectomy. Methods:Eighty-four patients who underwent pancreaticoduodenectomy were enrolled in this study. They were randomly divided into the EN group and the PN group. The program of isonitrogenous and isocaloric intake was taken in each group. The biochemical and clinical parameters were recorded and analyzed between the two groups. Results:Significant differences were found in total complications,initiation of soft diet,hospital cost and liver function on the 7th postoperative day (P < 0.05). The incidence rate of complications was higher in PN group(33. 3%) than PD group(14.3%)(χ2 = 4.200,P = 0.040);The hospital cost was higher and initiation of soft diet was later in PN group than in PD goup[(64 650 ± 11 977)Yuan vs. (51 358 ± 5 114)Yuan,t = 6.614,P = 0.003;(76.1 ± 12.3)h vs. (44.5 ± 7.1)h,t = 14.375,P = 0.017]. And liver function was much better in EN group than in PN group. No significant differences were found in mortality,anastomotic leakage,hemorrhage,delayed gastric emptying,nutritional status and postoperative hospital stay between EN group and PN group. Conclusion:EN support can improve the liver function,reduce the complications and hospital cost,and help soft diet initiation of patients undergoing pancreatoduodenectomy. EN should be recommended as a regular treatment for patients who received pancreaticoduodenectomy.