Abstract： Objective： To observe the intervention effect of Changyi jian assisting routine chemotherapy on immune function and cancer related fatigue(CRF) in patients after surgery for colorectal cancer. Methods： A total of 84 cases of patients who underwent surgery for colorectal cancer were divided into the treatment group and the control group according to the random number table method， 42 cases in each group. Both groups were given routine FOLFOX4 chemotherapy， which was the perfusion of fluorouracil， calcium folinate and oxaliplatin； the control group was additionally given symptomatic and supportive treatment；the treatment group was additionally given Changyi jian based on the treatment of the control group. Both groups were treated for three months. Before and after treatment，the scores of Cancer Fatigue Scale (CFS)， and the levels of T lymphocyte subsets including CD3 + ， CD4 + ， CD8 + and CD4 +/CD8 + in peripheral blood were compared between the two groups. After treatment， the number of cases of decrease in leukocyte， platelet， and hemoglobin was compared between the two groups. Results： Compared with those before treatment in the same group， the scores of physical fatigue and general fatigue in CFS in the two groups were decreased(P＜0.05)，and the two scores in the treatment group were lower than those in the control group(P＜0.05). Compared with those before treatment in the same group，the levels of CD3+，CD4+，and CD4+/CD8+ in the two groups were decreased(P＜0.05)，and the levels of CD8+ were increased(P＜0.05). When compared with those in the control group after treatment，the levels of CD3+，CD4+，and CD4+/ CD8 + in the treatment group were increased(P＜0.05)，and the level of CD8 + as well as the cases of decrease in leukocyte was decreased(P＜0.05). Conclusion：In the treatment of patients after surgery for colorectal cancer，Changyi jian assisting routine chemotherapy can effectively relieve their CRF and improve immune function，with lesser bone marrow suppression.