〔Abstract〕 Objective To explore the central role of interleukin(IL)-25 in allergy of eosinophil asthma. Methods Forty 4-5 week-old C57BL/6 mice were used in this study(n=10). Mice were randomly divided into 4 groups: WT+shRNA NT group, WT+HDM group, IL-25 shRNA+IL-25 group, and IL-25 shRNA+IL-25+HDM group. According to each group′s treatment requirement, mice were treated with house dust mite and/or IL-25 by intranasal infusion. HE staining and PAS staining were used for lung tissue section staining and pathological analysis. The levels of type 2 cytokines in bronchoalveolar lavage fluid(BALF) were determined by ELISA. Flow cytometry(FCM) was used to determine the number of type 2 helper T(Th2) cells, the group 2 innate lymphoid cells(ILC2) and eosinophils in lung tissues. Mice were treated with FITC-labeled DQ-ovalbumin(DQ-OVA) by intranasal infusion to determine the antigen presentation ability of eosinophils infiltrated in the lungs. Results HE staining and PAS staining results showed that, compared with WT+shRNA NT group, a large amount of mucus and a large number of eosinophil infiltration were found in the lungs, and subcutaneous thickening of inflammatory airway were observed in the pulmonary vessels, alveolar ducts and the whole alveoli in IL-25 shRNA+IL-25+HDM group. In the IL-25 shRNA+IL-25 group, only a small amount of mucus and a small amount of eosinophil infiltration were found in the lungs, and a small amount of subcutaneous thickening of inflammatory airway were observed in pulmonary vessels, alveolar ducts and the whole alveoli. There was no significant difference in WT+HDM group. Compared with WT+shRNA NT group, the levels of IL-25, IL-4,IL-5,IL-13, IL-33 and interferon-γ(IFN-γ) in BALF significantly increased; the levels of infiltrated Th2, ILC2 and eosinophils in the lung significantly increased; the fluorescence levels of FITC-labeled DQ-OVA in eosinophils infiltrated in lungs significantly increased in IL-25 shRNA+IL-25+HDM group(P<0.05). IL-25 shRNA+IL-25 group mice also showed an increase in the above measurements, but the amplitude were limited(P<0.05). WT+HDM group had no significant difference. Conclusion IL-25 plays an essential role in the allergy and eosinophil antigen presentation processes in eosinophil asthma mice.