Abstract: Objective: To investigate the role of Pro-and Ant-i inflammatory cytokine in sepsis induced lung injury. Methods: Sepsis was induced in mice by cecal ligation and puncture (CLP).Sham operation group underwent the same manipulation but without CLP.Pro-inflammatory cytokine (TNFα,IL-1β,IL-6) and Ant-i imflammatory cytokine (IL- 4) gene expression of lung tissue were assessed by RT-PCR. Results: A significant increase in TNF,IL-1and IL-6gene expression was observed at 3and 12hours after CLP.The level of TNFαand IL-1βat 3hours was higher than 12 hours,and the level of IL-6gene expression at 12hours was slightly higher than 3hours.While no difference was seen in IL-4gene expression between CLP and sham group. Conclusion: The unbalance of pro-and ant-i inflammatory cytokine may play a key role in the development of sepsis induced lung injury.