Objective To investigate the changes of inflammatory factors in bronchoalveolar lavage fluid (BALF), lung tissue, and serum of a rat pneumonia model induced by inhalation of lipopolysaccharides (LPS). Methods Three days after modeling by LPS 4 mg/mL inhalation, 15 min/d, was conducted while monitoring the particle size distribution and aerosol concentration of LPS, the degree of inflammation in lung tissues of rats in each group was observed via HE staining, and neutrophils in BALF were counted by microscope. The contents of interferon gamma (IFN-γ), interleukin-1 beta (IL-1β), IL-4, IL-5, IL-6, IL-10, IL-13, tumor necrosis factor alpha (TNFα), and KC/GRO in lung tissue, serum, and BALF were detected by Meso Scale Discovery. Results The lung histopathology of model rats displayed focal and diffuse alveolar epithelial necrosis with shedding and the aggregation and infiltration of inflammatory cells. The particle size distribution of atomized LPS was as follows, Dv(10) = 0.6974 μm, Dv(50) = 3.387 μm, Dv(90) = 8.836 μm. The aerosol concentration of LPS was 4.08 g/m³, and the calculated inhalation dose for rats was 47.10 mg/kg. The neutrophil count (P<0.01) and contents of IL-1β, IL-6, and TNF-α (P<0.05, P<0.001, P<0.001) in the BALF, and the contents of IL-1β, IL-6, and KC/GRO in lung tissue (P<0.01, P<0.05, P<0.01), of model rats were significantly increased. No biologically significant changes were observed in inflammatory factor levels in the serum. Conclusions In the acute pneumonia model induced by inhalation of LPS, significant changes in inflammatory factors such as IL-1β, IL-6, KC/GRO, and TNFα were observed in both lung tissue and bronchoalveolar lavage fluid (BALF), while no notable changes in these inflammatory factors were detected in serum. This indicates that the inflammation responses are primarily localized in the lungs.