Abstract: Objective 　To study the effect of total parenteral nut rition ( TPN) supplemented with glutamine and arginine on the postoperative immune function of the patient s with colorectal cancer. Methods 　According to the operative methods with match, the patient s with colorectal cancer between August 2005 and August 2006 were divided into experiment group and control group, including 24 cases respectively. From the first day to the seventh day af ter operation, TPN supplemented with glutamine and arginine was used in the experiment group, while standard TPN was used in the control group. The humoral immune markers ( IgA, IgG, IgM) and cellular immune markers (CD3, CD4, CD8, CD4/ CD8) were measured in all cases before the operation, on the fourth day and the eighth day af ter operation. Results 　Compared with the preoperative immunity, the levels of humoral and cellular immunity declined on the fourth day, but they resumed on the eighth day after operation. Compared with the cont rol group, IgA、IgG、CD3 、CD4 、CD4/CD8 in the experiment group on the eighth day af ter operation increased significantly ( P < 0. 05) . Conclusion 　TPN supplemented with glutamine and arginine can improve the immune function of patient s with colorectal cancer after operation effectively.