Abstract: Objective: The aim of this study was to develop a functional teabags for enhancing immunity with green tea, Astragali radix, Codonopsis radix, Lycii fructus and Jujubae fructus. Methods: Sensory evaluation was used as indicator, the best formula of the teabags was optimized by orthogonal test combined with fuzzy mathematics comprehensive evaluation method. And the total polysaccharide content was detected by the phenol-sulfuric acid method. SPF-grade Kunming mice were randomly divided into blank control group, model control group, positive control group and teabags group with low-, medium- and high- dose (0.52, 1.04, 1.56 g/kg BW). Except for the blank control group, the immunosuppressive model was prepared by intraperitoneally injected with cyclophosphamidein in all groups, and the body weight and organ index of mice were measured after 21 days of continuous administration. After those processes, CD3⁺ cells, CD4⁺ cells, CD8⁺ cells and CD4⁺CD8⁺ cells were detected by flow cytometry in the spleen of mice. In addition, the level of interferon-γ (IFN-γ) in mouse serum was detected by ELISA. Results: In the optimal formulation of the teabags, the amounts of Astragali radix, Codonopsis radix, Lycii fructus, Jujubae fructus and green tea were 13.00%, 26.30%, 20.50%, 20.50% and 19.70% of the total mass of the teabags contents, respectively. In addition, the content of polysaccharide was 33.84±0.52 mg/g. The efficacy test results showed that compared with the blank control group, the body weight and thymus index of mice in the model control group were significantly declined (P<0.05), CD3⁺ cells, CD4⁺ cells, CD8⁺ cells and CD4⁺CD8⁺ cells ratio were significantly reduced (P<0.05), and IFN-γ content in serum significantly decreased (P<0.05), which indicated that the immunosuppressive model was established successfully. Compared with the model control group, the body weight, thymus index, CD3⁺ cells, CD4⁺ cells, CD8⁺ cells and CD4⁺CD8⁺ cells ratio, and the serum IFN-γ content of mice in the low dose group significantly increased (P<0.05). The thymus index, CD4⁺ cells, CD8⁺ cells and CD4⁺CD8⁺ cells ratio of mice in the medium dose group significantly increased (P<0.05). Additionally, the thymus index of mice in the high dose group significantly increased (P<0.05). Overall, the immunomodulation effect of the teabags in the low-dose group was better than that of the medium- and high-dose group. Conclusion: Immunomodulatory teabags had an immune-enhancing effect, and its effect is related to the regulation of the T cell immune mechanism.