Abstract: Ojbective: To study the effects of erythromycin treatment to endotoxin-induced ALI（acute lung injury） in rat model.Methods: The rat model of ALI was made by injecting lipopolysaccharide（LPS） with a dose of 4mg/kg into vena caudalis.54 male SD rats were randomly divided into three groups: control group（NC）,experiment group（LPS） and treatment group（EY）,18 rats every group.In control group physiologic saline was injected,in experiment group LPS was injected,in treatment group LPS was injected as time as erythromycin injectable powder intraperitoneal injection（50 mg/kg）.Measured the levels of IL-1β,IL-6,TNF-α,IL-8,IL-10 in serum and alveolar wash liquid of 54 rats by enzyme-linked immunosorbent assay（ELISA）.Results: Compare treatment group with experiment group,PaO₂ and pH stepped up,PaCO₂ stepped down,lung coefficient was（0.62±0.07 vs 0.96±0.13,P＜0.05）,lung water content（85.76±0.56 vs 82.88±0.47,P＜0.05）,lung permeability index（7.41±0.61 vs 12.26±0.58,P＜0.05）,all decreased significantly,IL-1β,IL-6,IL-8 and TNF-α in serum and alveolar wash liquid stepped down,however,IL-10 stepped up significantly.The lesion of lung tissue in treatment group was lighter than that in experiment group through pathology observing.Conclusion: Erythromycin can