OBJECTIVE： To observe clinical efficacy and safety of Astragalus injection combined with neoadjuvant chemotherapy and three dimensional conformal radiotherapy in the treatment of colorectal cancer. METHODS： A total of 80 patients with medium and advanced colorectal cancer were selected from oncology department of our hospital during Jun. 2010 to Jun. 2014， and divided into observation group and control group according to random number table， with 40 cases in each group. Control group received neoadjuvant chemotherapy combined with three-dimensional conformal radiotherapy. Observation group was additionally given Astragalus injection 10-20 mL added into 5％ Glucose injection 250-500 mL， ivgtt， qd， on the basis of control group. A treatment course lasted for 21 d， and both groups received 3 courses. Short-term efficacies as well as immune indexes [CD3+， CD4+， CD4+/CD8+ and NK cells] before and after treatment were observed in 2 groups. The occurrence of ADR and survival situation were compared between 2 groups. RESULTS： Clinical response rate of observation group was 87.5％， which was slightly higher than that of control group （77.5％）， but there was no statistical significance （P＞0.05）. Before treatment， there was no statistical significance in immune index levels between 2 groups （P＞0.05）. After treatment， NK cells， CD3+， CD4+ and CD4+/CD8+ levels of control group were decreased significantly， which was significantly lower than observation group， with statistical significance （P＜0.05）. There was no statistical significance in the incidence of ADR between 2 groups （P＞0.05）. Two-year survival rate of observation group was significantly higher than that of control group； the recurrence rate and distant metastasis rate were significantly lower than control group， with statistical significance （P＜0.05）. CONCLUSIONS： Astragalus injection not only can improve therapeutic efficacy of neoadjuvant chemotherapy in patients with colorectal cancer， balance inflammatory state， improve survival rate， reduce recurrence rate and distant metastasis rate with good safety.