To explore the effects of camptothecin(CPT) on acute lung injury(ALI). The experiment was divided into blank control group, single drug group, model group, model plus drug group. LPS-induced RAW264.7 cells were used as inflammatory cell models and RNA was collected. Real-time quant. PCR was used to detect the changes of IL-6 and IL-1β genes. The mouse model of acute lung injury was constructed by intranasal injection of LPS. After 12 h, lung tissue and bronchoalveolar lavage fluid were collected. Paraffin sectioning techniques were used to assess changes in lung histopathol. The secretion of IL-6 and IL-1β in bronchoalveolar lavage fluid was detected by ELISA. Myeloperoxidase(MPO) detection technique was used to detect the activity of MPO in lung tissue. The ratio of the wet weight to the dry weight of the lungs was measured to evaluate the edema of the lungs. In result, in vitro, CPT pretreatment significantly inhibited the increase of IL-6 and IL-1β gene levels. In vivo experiments, CPT pretreatment can significantly alleviate the pathol. damage of lung tissue, significantly inhibit the increase of MPO activity, significantly inhibit the secretion of IL-6 and IL-1β in BALF, and significantly allivate the edema of the lung. In conclusion, CPT has a significant therapeutic effect on LPS-induced ALI.