Sepsis induced acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are lifethreatening disorders. Acute Physiology and Chronic Health Evaluation (APACHE) scores and several plasma biological markers have been identified to predict the death or treatment outcome of sepsis induced ALI. Immune related microRNAs also have the potential as biomarkers to monitor this kind of disease. A total of 44 patients with severe sepsis, 102 patients with sepsis, and 19 healthy volunteers were enrolled in this study. Plasma miR-155 and miR-146a were determined by qRT-PCR. Genotyping analysis of miR146a rs2690164 was performed using PCR-restriction fragment length polymorphism assay. The relative plasma miR-155 and miR-146a concentrations were significantly increased in severe sepsis and sepsis-induced cases of ALI, compared with control subjects. The AUC of miR-155 and miR-146a for predicting 30-day mortality in ALI patients was 0.782 (95% CI 0.694 - 0.870) and 0.733 (95% CI 0.640 - 0.827), respectively. CC genotype of miR-146a rs2910164 was associated with worse treatment outcome of these patients. The current study provides evidence that the plasma miR-155 and miR-146a could be novel biomarkers for predicting the mortality and treatment outcome of sever sepsis and sepsis-induced acute lung injury.