Objective To establish a model of pulmonary blast injury in rats, to explore the expression changes in TNF-α and NF-κB at different time points of pulmonary blast injury. Methods Thirty-six SD rats were randomly divided into 6 groups: control group, 3, 6, 12, 24, and 48 h blast injury model group, with six rats in each group.At the end of the experimental time points, the animals were observed for signs of life and were sampled the lung tissue for pathological HE staining, fluorescence quantitative PCR and Western-blot to detect the expression level of TNF-α and NF-κB. Results HE staining showed that rat lung blast injury led to a large amount of lung tissue inflammation, alveolar wall thickening and other symptoms. Quantitative PCR showed that TNF-α and NF-κB mRNA expression in blast injury rats were significantly higher; Western-blot showed that, TNF-α increased gradually after the blast injury, and reached a peak at 12 h（3.76±0.17）, and then gradually decreased; expression of NF-κB expression with the extension of time gradually increased, the results were statistically significant. Conclusion Blast injury in lungs produces large amounts of inflammatory cytokines, and TNF-α and NF-κB mRNA and protein expression  is increased, resulting in injury of lung tissue.