〔Abstract〕 Objective To investigate whether Mitochondria-targeted antioxidant peptide SS-31 can inhibit the ozone(O3)-induced mice lung airway hyperresponsiveness and mucus hypersecretion. Methods Eight-week C57BL/6 mice were randomized into four groups, including phosphate buffer saline(PBS)+Air group, SS-31+Air group, PBS+O3group and SS-31+O3group. C57BL/6 mice were injected intraperitoneally with SS-31(10 mg/kg) one hour before ozone exposure, and then single-exposed to ozone at a concentration of 5.01×10-6mol/m3for 3 hours. After 24 hours, airway hyperresponsiveness(AHR) and bronchoalveolar lavage fluid(BALF) cells numbers were measured. Lung tissue schiff periodic acid shiff(PAS) staining, malondialdehyde(MDA), inflammatory factors(interleukin, IL)-1β, IL-6, IL-18 and monocyte chemoattractant protein-1(MCP-1)) and mucin factor(MUC5B)were detected, and the protein expression levels of NOD-like receptor thermal protein domain associated protein 3(NLRP3), pro-Caspase 1/Caspase 1(p20), Gasdermin D(GSDMD) and Cleaved GSDMD were determined by Western blot. Results O3exposure caused both mice lung airway hyperresponsiveness and mucus hypersecretion. However, SS-31 could inhibit the O3-induced airway hyperresponsiveness and mucus secretion, reduce the levels of oxidative stress and inflammatory factor mRNA expression, and downregulate the protein expression level of NLRP3 and the activated forms of Caspase 1 and GSDMD. Conclusion SS-31 could suppress O3-induced mice airway hyperresponsiveness and mucus hypersecretion by inhibiting the NLRP3/Caspase 1/GSDMD signaling pathway.