Abstract：Objective：To observe the clinical effect of modified Sijunzi tang combined with chemotherapy on advanced colorectal cancer. Methods：A total of 88 patients with advanced colorectal cancer were retrospectively selected and divided into the observation group and the control group according to different treatment methods，with 44 cases in each group. The control group was treated with chemotherapy，and the observation group was additionally treated with modified Sijunzi tang based on the treatment of the control group. The changes of Chinese medicine syndrome score，vascular endothelial growth factor(VEGF)，matrix metalloproteinase-2(MMP-2) and T cell subsets(CD3+，CD4+，CD8+) were compared between the two groups， and the adverse reactions during treatment were observed. Results： Before treatment， there was no significant difference in the comparison of the scores of abdominal distension， mental fatigue， poor appetite and thin and unformed stool as well as the total score between the two groups(P＞0.05). After treatment，the symptom scores and total score in the two groups were decreased when compared with those before treatment，and the symptom scores and the total score in the observation group was lower than that in the control group， the difference being significant(P＜0.05). Before treatment， there was no significant difference in the levels of MMP-2，VEGF and T lymphocyte subsets(CD3+，CD4+，CD8+ ) between the two groups(P＞0.05). After treatment， the levels of MMP- 2 and VEGF in both groups were lower than those before treatment(P＜0.05)，and the levels of MMP-2，VEGF and CD8+ in the observation group were lower than that in the control group，CD3 + and CD4 + were higher than that in the control group(P＜0.05).The incidence of gastrointestinal reaction，liver and kidney function injury， leucopenia and thrombocytopenia in the observation group were 13.6% ， 9.1% ， 20.5% and 6.8%，respectively，which were lower than those of 31.8%，29.5%，45.5% and 27.3% in the control group，differences being significant(P＜0.05). Conclusion： Sijunzi tang can reduce clinical symptoms， decrease levels of serum MMP- 2 and VEGF，and regulate immune function in patients with advanced colorectal cancer chemotherapy.