Objective To observe the immunological mechanism of glycyrrhizic acid ointment on chronic eczema mouse model. Methods Mice were randomly divided into blank control group,model control group,base material group, dexamethasone acetate cream group,glycyrrhizic acid ointment high,medium and low dose groups.Except for the blank control group,chronic eczema mouse model was established by chronic repeated 2,4-nitrochlorobenzene stimulation.The contents of IL-4, IL-18,IFN-γ in serum and the T lymphocyte subpopulation in the peripheral blood were all determined after 14 days. Results Glycyrrhizic acid ointment in high,medium groups could significantly reduce the contents of interleukin (IL)-2,IL-5,IL-6,IL-18,interferon(IFN)-γ in serum,with significant differences as compared with the model control group(P<0.01 or P<0.05).The content of IL-4 in serum was significantly increased in the glycyrrhizic acid ointment high,medium groups as compared with the model control group (P<0.01 or P<0.05).Compared with model control group,CD+4T lymphocyte percentage and CD+4/CD+8T in peripheral blood were significantly increased,and CD+8T lymphocyte percentage decreased significantly (P<0.01 or P<0.05). Conclusion Glycyrrhizic acid ointment's effect of treating chronic eczema may be related to regulating the balance of Th1 and Th2 and correcting the immune disorders.