【Abstract】Objective To investigate the role of interleukin-10（IL-10） and interleukin-18 （IL-18） in the pathogenesis of acute lung injury in experimental severe acute pancreatitis.Methods Forty-eight SD rats were divided into control group and SAP group by the random data table. The model of experimental severe acute pancreatitis was established by injection of 3.5% sodium taurocholate into the bili-pancreatic duct. Lung wet weight index, ascities and level of serum amylase, IL-10 and IL-18 were quantitatively measured in different time. Intrapulmonary expressions of IL-10 mRNA and IL-18 mRNA were detected by semiquantitative RTPCR. The histopathology of pancreas and lung were observed under the light microscope.Results Lung wet weight index, ascities, level of serum amylase, IL-10 and IL-18, intrapulmonary expressions of IL-10 mRNA and IL-18 mRNA were significantly increased in SAP group (P＜0.01). The level of serum IL-18 and intrapulmonary expression of IL-18mRNA are positively correlated with lung wet weight index （r=0.68,P＜0.01; r=0.72,P＜0.01） and lung injury score （r=0.74,P＜0.01; r=0.79,P＜0.01) respectively, whereas the level of serum IL-10 and intrapulmonary expression of IL-10 mRNA are negatively correlated with lung wet weight index（r=-0.62,P＜0.01; r=-0.69,P＜0.01） and lung injury score（r=-0.66,P＜0.01; r=-0.60,P＜0.01）. Conclusion IL-18 may play a key role in the pathogenesis of acute lung injury in experimental severe acute pancreatitis, and IL-10 exerts the protection role in this process.