Objective To discuss the0. possible protective mechanism of Qingfei Chengqi Decoction on acute lung injury in rats with severe abdominal infection. Methods Totally 30 Wistar rats were randomized into the sham operation group

model group and TCM group

with 10 in each. The model group and TCM group were treated with simulated gastric fluid and E. coli intraperitoneal injection to create abdominal infection model. The sham operation group was treated with equal volume of 10% BaSO4 nutrient broth. One day before modeling

TCM group was gavaged with Qingfei Chengqi Decoction solution（1.5g crude drug/ml）2ml/time for each rat and 3 times daily. The TCM group was given gastric administration again 30 min before modeling together 4 times. The sham operation group and model group were given equal volume of normal saline. Six hours after modeling

the protein level

cytological classification

endotoxin level

intercellular adhesion molecule-1（ ICAM-1）

monocyte chemoattractant protein-1（ MCP-1） and lung wet /dry weight（ W /D） ratio in bronchoalveolar lavage fluid（ BALF） were detected in each group. The pathological changes of lung tissue were observed. Results Comparing with the sham operation group

the protein level and neutrophil level in BALF were significantly increased in the model group and TCM group（ P < 0. 05）. Comparing with the sham operation group

the levels of endotoxin

ICAM-1

MCP-1 and W /D ratio were significantly increased in the model group（ P < 0. 01）. Comparing with the model group

the levels of endotoxin

MCP-1 and W /D ratio were significantly decreased in TCM group（ P < 0. 01）. Comparing with the model group

the interstitial edema

hemorrhage

inflammatory cell infiltration

fibrous hyperplasia of alveolar wall and other pathological lesions were alleviated in TCM group. Conclusion Qingfei Chengqi Decoction can reduce acute lung injury in rats with severe abdominal infection

which may be relevant to decreasing the levels of endotoxin and MCP-1 in BALF.