ObjectiveTo study the possbility of using intranasal instillation of fine particulate matter (PM2.5) combined with inhalation of ozone (O3) to establish mouse model of combined pulmonary fibrosis and emphysema (CPFE), and to provide a reference for the establishment of CPFE model.MethodsMale C57/BL6 mice were divided randomly into phosphate buffer saline (PBS) intranasal instillation+air inhalation group, PBS intranasal instillation+O3 inhalation group and PM2.5 intranasal instillation+O3 inhalation group, with 8 mice in each group. The mice were intranasally instilled with PBS or PM2.5 suspension (7.8 mg/kg) followed by air or ozone inhalation 24 hours later, twice a week over 8 weeks. Lung function, bronchoalveolar lavage fluid (BALF) cell counts and classification were detected, the pathological changes of lung tissues in hematoxylin-eosin staining were observed, including inflammation scores and mean linear intercept (Lm). The thickness of collagen deposition in subepithelium was measured in lung tissues in Masson staining, and simultaneously hydroxyproline contents in lung tissues were determined.ResultsCompared to PBS instillation+air inhalation group, inspiratory capacity (IC), total lung capacity (TLC) and chord compliance (Cchord) were increased, FEV25 (the forced expiratory volume at 25 ms)/FVC (forced vital capacity) was decreased, total cell counts in BALF, Lm and lung inflammatory scores were increased, the thickness of the subepithelial collagen layer (SEc/Pbm) or hydroxyproline contents was not changed in PBS instillation +O3 inhalation group; IC was decreased, functional residual capacity (FRC) was increased, TLC was increased, Cchord was decreased, FEV25/FVC and FEV50 (the forced expiratory volume at 50 ms)/FVC were decreased, total cell counts in BALF, Lm, lung inflammatory scores, SEc/Pbm and hydroxyproline contents were increased in PM2.5 instillation+O3 inhalation group. Compared to PBS instillation+O3 inhalation group, IC was decreased, FRC was increased, Cchord was decreased, FEV25/FVC and FEV50/FVC were decreased, total cell counts in BALF, Lm, lung inflammatory scores, SEc/Pbm and hydroxyproline contents were increased in PM2.5 instillation +O3 inhalation group.ConclusionCPFE mouse model can be successfully established by PM2.5 intranasal instillation combined with ozone inhalation for consecutive 8 weeks.