Objective To explore the effect of immune-enhancing enteral nutrition support combined with chemotherapy on the nutritional status and immune function of elderly patients with advanced colorectal cancer.Methods Sixty elderly patients with advanced colorectal cancer who were treated at Huai′an First Hospital Affiliated to Nanjing Medical University from May 2017 to May 2020 were selected as the research objects.All patients were divided into observation group and control group according to the random number table method,with 30 cases in each group.The control group received chemotherapy,the observation group was combined with immune-enhanced enteral nutrition support on the basis of the control group.Nutritional status indicators(body mass index[BMI],albumin[Alb]content,transferrin[TF]content),immune function indicators(T lymphocyte[CD3+,CD4+,CD8+])levels and complications were compared between the two groups before and after treatment.Quality of life score (Karnofsky [KPS],Zubrod performance status[ZPS],quality of life score [QOL])was used to evaluate the prognosis.Results After treatment,BMI,Alb,TF,CD3+,CD4+,CD8+,KPS and QOL scores of observation group were higher than those of control group,and the ZPS scores were lower than those of the control group,the differences were statistically significant(P＜0.05).The total incidence of complications in the observation group was 10.00%(3/30),lower than 26.67% (8/30)in the control group,and the difference was statistically significant(P＜0.05).Conclusion Immune-enhancing enteral nutrition support com-bined with chemotherapy can effectively improve the nutritional status and immune function of patients,and can promote the smooth implementation of treatments.After the combined treatment of the two,the risk of complications is lower and the quality of life has also been significantly improved.This therapy has high clinical value and it is recommended to be further promoted and applied.