OBJECTIVE： To study the effects of the extract from ethyl acetate part of Ferula sinkiangensis on immune function of colon cancer model mice， and to provide reference for further development and utilization of plants of the genus Ferula. METHODS： Colon cancer model mice were induced by incubated with colon cancer CT-26.WT cell. 50 model mice were randomly divided into model group （normal saline， i.g.）， cisplatin group （5 mg/kg， i.p.） and ethyl acetate part of F. sinkiangensis low-dose， medium-dose and high-dose groups （1.0， 2.0， 3.0 g/kg， calculated by crude drug， i.g.）， with 10 mice in each group. Other 10 normal mice were included in blank group （normal saline， i.g.）. Cisplatin group was given medicine every other day， and other groups were given medicine once a day， for consecutive 10 d. After medication， the inhibition rate of tumor and spleen index were determined. Flow cytometry was adopted to detect the number of blood T lymphocyte subsets CD3+， CD4+， CD8+ and B lymphocytes CD19+； CD4+/CD8+ value was calculated. ELISA method was adopted to detect the content of immune protein IgM and IgG in serum of mice. RESULTS： Compared with blank group， spleen index of mice was increased significantly in model group （P＜0.01）. There was no statistical significance in the number of CD3+， CD4+， CD8+ and CD19+ cells in the blood， as well as the contents of lgM and lgG in the serum （P＞0.05）. Compared with model group， the tumor mass of mice in ethyl acetate part of F. sinkiangensis groups were significantly reduced （P＜0.01）， inhibitory rate of tumor was more than 40％. The spleen index， the number of CD3+ and CD4+， CD4+/CD8+ value， the contents of IgM and IgG in serum were increased significantly in ethyl acetate part of F. sinkiangensis medium-dose and high-dose groups （P＜0.05 or P＜0.01）. The number of CD19+ cells in blood was decreased significantly in ethyl acetate part of F. sinkiangensis groups（P＜0.05 or P＜0.01）. There was no statistical significance in the number of CD8+ cells in blood （P＞0.05）. CONCLUSIONS： The extract from ethyl acetate part of F. sinkiangensis shows inhibitory effect on colon cancer model mice， and can significantly improve cellular immunity function and humoral immunity function.