Objective:To investigate the protective effect of baicalin on acute lung injury（ALI） rats induced with lipopolysaccharide（LPS）.Method:SD rats were randomly divided into 6 groups（n=10）: control

ALI model

dexamethasone（5 mg · kg-1） and baicalin groups（50

100

200 mg · kg-1）.After 1 h of the last administration

the model of ALI was established by intratracheal instillation of LPS.After 6 h of the LPS instillation

the serum was collected for determinating the interleukin（IL）-1β

IL-8 and tumor necrosis factor（TNF）-α levels.In addition

the ratios of lung wet to dry weight and water content were also measured.The activity of myeloperoxidase（MPO） and cyclooxygenase（COX）-2 in lung was determinated.Result:Compared with control group

ALI group exhibited a higher wet to dry radio and water content in lung（P<0.05）.Compared with ALI model group

baicalin significantly decreased the levels of IL-1β

IL-8 and TNF-α in serum（P<0.05）

reduced the wet to dry ratio and water content in a dose-dependent manner（P<0.05）.Moreover

baicalin significantly decreased the activity of MPO and COX-2 in lung（P<0.05）.Conclusion:Baicalin had a protective effect on ALI rats induced with LPS and the mechanism maybe related to the suppression of inflammation.