Abstract: Objective:To study the effect of chicory polysaccharide on immune function in immunosuppressed mice. Methods:ICR mice were randomly divided into blank group,model group,drug group(Piantai),CP low,medium and high dose group. In addition to the blank group,the other groups used cyclophosphamide to cause immunosuppressed mouse model. Body weight,immune organ index,peripheral blood leukocytes and erythrocyte count,delayed hypersensitivity-induced toe swelling,peritoneal macrophage phagocytosis,serum levels of lysin and activity levels of interleukin 2(IL-2),interleukin 6(IL-6)and tumor necrosis factor α(TNF-α)in each group of mice were determined,respectively. Results:Compared with the model group,CP high dose group could significantly increase net body weight rate,immune organ index,macrophage phagocytosis rate and index,number of leukocytes and erythrocyte,and decrease toe swelling in immunosuppressed mice(P<0.05). Meanwhile,CP high dose group could also significantly improve phagocytosis of mouse peritoneal macrophages,serum lysin content,and regulate immune cytokines in immunosuppressed mice. Conclusion:CP could enhance immune activity in immunosuppressed mice.