Purpose: To investigate the effect of the Ma-Xin-Di-Tan (MXDT) decoction on ovalbumin-induced allergic asthma (AA) in mice. Methods: Asthma was induced in mice by ovalbumin (OVA) injection, and different doses of MXDT (150, 300, and 600 mg/kg/day) were administered orally for 28 days. Pathological changes in lung tissues were examined, while levels of cytokines, including interleukin (IL)-4, IL-6, IL-17, interferon (IFN)-γ, and transforming growth factor (TGF)-β, were determined using enzyme-linked immunosorbent assays (ELISAs) of the bronchoalveolar lavage fluid. Toll-like receptor (TLR)-4, GATA-binding protein (GATA)-3, Ox40 ligand (OX40L), indoleamine 2,3-dioxygenase (IDO), forkhead box P3 (Foxp3), and T box expressed in T cells (T-bet) levels were determined in lung tissues by western blot analysis. Results: MXDT inhibited the inflammatory reaction of lung tissues in OVA-challenged mice. After treatment with MXDT, levels of IL-4, IL-6, IL-17, and TGF-β were downregulated, whereas IFN-γ levels were upregulated. In addition, MXDT decreased TLR-4, GATA-3, and OX40L levels in lung tissues but increased the expression of Foxp3, T-bet, and IDO. Conclusion: MXDT has antiallergic effects on OVA-induced AA in mice; the possible molecular mechanisms might involve the inhibition of inflammatory reactions and modulation of Th1/Th2 cytokine balance.