Object To study the expression of miRNA-146a in sepsis-induced acute lung injury (ALI) patients and its effect on the inflammation in mouse models.Methods miRNA-146a expression in peripheral blood was determined in sepsisinduced ALI patients and healthy volunteers by qRT-PCR.Sepsis-induced ALI mouse model were reproduced by LPS treatment and miRNA-146a mimic,miRNA-146a NC and miRNA-146a inhibitors were injected through trachea.The expressions of miRNA-146a,TNF-α,IL-1β and COX-2 mRNA were determined by qRT-PCR 24h after the intervention.Results The miRNA-146a expression in peripheral blood significantly increased in severe sepsis with ALI patients,compared with the control subjects.For mouse model,the expressions of TNF-o,IL-1β and COX-2 mRNA significantly decreased in miRNA-146a group,while increased in miRNA-146a inhibitor group compared with miRNA-146a NC group (P＜0.05).The TNF-α and IL-1β expressions significantly decreased in miRNA-146a inhibitor+COX-2 inhibitor group compared with miRNA-146a inhibitor group (P＜0.05).Conclusion MiR-146a treatment can effectively alleviate the lung inflammation in sepsis-induced ALI mice.