Abstract: Objective: In this study, the prebiotic potential of Red-edge tea polysaccharides (RETPS) and the anti-allergic activity of its metabolites in vitro were investigated. Methods: The prebiotic potential of RETPS was investigated by colonic fermentation model in vitro. Then, the activation model of anaphylaxis effector cells (rat basophilic leukemia (RBL)-2H3 cells) and differentiation model of immunosuppressive cells (regulatory T cell (Treg) cells) in anaphylaxis were conducted to evaluate the anti-allergic activity of metabolites after RETPS fermentation in vitro. Results: RETPS could modulate the structure of intestinal flora by increasing the relative abundance of Bifidobacteriaceae and Leuconostocaceae, and promote the production of propionic acid and butyric acid, suggesting that RETPS has prebiotic potential. Meanwhile, the results of RBL-2H3 cell model showed that colon fermentation products of RETPS could significantly reduce the release rate of β-hexosaminidase, inhibiting depolymerization of F-actin, and stabilizing mast cells. Moreover, the intervention of colon fermentation products of RETPS could increase the proportion of Treg (9.19%±2.59% up to 41.05%±0.48%) in the Treg cell differentiation model, inducing the differentiation of Treg cells. Conclusion: RETPS showed prebiotic potential, and colon fermentation products of RETPS have anti-allergic activity in vitro. Therefore, RETPS was expected to be applied to the development of anti-allergic special foods.