〔Abstract〕 Objective To investigate the role of protein demethylase of lysine-specific demethylase 2 A(KDM2 A) in airway inflammation and remodeling in rats with bronchial asthma. Methods Intraperitoneal injection of chicken ovalbumin(OVA) sensitized aerosol to stimulate the asthma rat model. Eighteen 6-8 weeks old SPF SD female rats were randomly divided into 3 groups, namely the control group, the asthma group for 4 weeks, and the asthma group for 8 weeks. After the success of the asthma model, the infiltration of inflammatory cells in the trachea and perivascular of the lung tissue was observed by HE staining; Goblet cell proliferation and mucus secretion were observed by PAS staining; Masson staining was used to observe the fibrosis of airway wall; The proliferation of airway smooth muscle was observed by fluorescence immunohistochemistry; The protein expression level of KDM2 A was detected by Western blot. Results The inflammatory scores and inflammatory cell counts of rats in the asthma 4-week group and the asthma 8-week group were higher than those in the control group. There was a statistically significant difference in the above indicators between the asthma two groups(P<0.01). Compared with the control group, the proliferation of goblet cells and mucus secretion in the airway epithelium, the deposition of collagen fibers in the lung tissue and the proliferation of bronchial smooth muscle cells increased in the asthma groups(P<0.01). With the prolonged OVA sensitization time, airway inflammation and airway remodeling changes were more severe in the asthma 8-week group than those in the asthma 4-week group. The results of Western blot showed that the expression of KDM2 A in the lung tissues of the asthmatic 4-week group and the asthmatic 8-week group was higher than that of the control group, and the expression of KDM2 A in the asthma 8-week group was also higher than that of the asthma 4-week group. The differences were statistically significant(P<0.01). The expression of KDM2 A protein in lung tissue of rats in each group was positively correlated with airway inflammation score, total number of inflammatory cells, goblet cell mucus secretion score, lung tissue fibrosis ratio, and airway smooth muscle hyperplasia area(allP<0.01). Conclusion KDM2 A may play an important role in the pathogenesis of airway inflammation and airway remodeling in bronchial asthma.