Abstract: Objective To study the role of Chinese herbal medicines（astragalus mongholicus and salvia miltiorrhiza）for supplementing Qi and activating blood circulation in prevention and treatment of acute lung injury（ALI）. Methods Forty-eight male Sprague Dawley rats were randomly divided into normal control group,model control group,and Chinese herbal medicine group（16 in group）.Animals in model control group and normal control group received intra-gastric 2ml normal saline（NS） daily for a week,those in herbal medicine group received intra-gastric 2ml herbal medicine liquid（0.25g/ml） daily for 1 week.ALI models were established by intra-tracheal lipopolysacchride（LPS） drip for model control group and Chinese herbal medicine group,and by intra-tracheal NS drip for normal control group.Lung index（LI）,lung permeation index（LPI）,and index of quantitative assessment（IQA） were monitored,and morphological changes in the lungs were observed. Results The LI（4.24±0.37）,LPI（0.88%±0.20%）,and IQA（17.7%±6.1%） were significantly lower while the PaO2（98.83±2.74mmHg） and SaO2（96.76 %±1.19%） were significantly higher in Chinese herbal medicine group than those in model control group（P＜0.01）.However,no significant difference was observed in the lung structure between Chinese herbal medicine group and normal control group（P＞0.05）. Conclusion Astragalus mongholicus and salvia miltiorrhiza play a significant role in prevention and treatment of ALI.