Abstract: Objective To investigate the effect of rosiglitazone(RSG) on acute lung injury (ALI) murine model and to explore the possible mechanism. Methods BLAB/c (n=24) mice were randomized into control group, ALI model group, RSG group and GW9662 group. The percentages of the inflammation cells in the bronchoalveolar lavage fluid (BALF) and the histopathological changes of the lung tissues were examined to reflex the degree of inflammation. Meanwhile, the levels of inflammatory cytokines were measured by ELISA. The expression of RORγt and PPARγ at mRNA and protein levels in the lung tissues was determined by RT-qPCR and Western blotting respectively. Results Compared with control group, the percentage of neutrophils and the contents of the inflammatory cytokines in LPS group were significantly increased in BALF（P<0.05）. Meanwhile, elevated mRNA and protein levels of RORγt suggested increased number of Th17 cells. Compared with LPS group, the degree of lung inflammation decreased in RSG group accompanied with low expression of RORγt and high expression of PPARγ（P<0.05）. GW9662 significantly antagonized the protective effect of rosiglitazone, showing obvious mouse lung tissue inflammation ,and higher mRNA and protein levels of RORγt as compared with RSG group（P<0.05）. Conclusions Rosiglitazone attenuates lung inflammation by regulating the polarization of Th17 cells in a murine ALI model induced by LPS.