Abstract: Objective　To investigate the changes of plasma microRNA-223(miR-223) and HMGB-1 in pediatric sepsis patients. Methods　There were 49 children with sepsis enrolled in the study (sepsis group)，severe sepsis group (n=25) and general group (n=24). Meanwhile, 50 healthy children (normal control group) were selected as control group. The expression levels of plasma miR-223and HMGB-1 (high mobility group box 1) were detected. The predictive values of miR-223and HMGB-1 in plasma of children with sepsis were evaluated by receiver operatingcharacteristic (ROC) curve. Results　The plasma miR-223 and HMGB-1 expression levels in severe sepsis group and general group were up-regulated compared with those in the normal control group (F=63.02, 76.32, P<0.05). The area under ROC curve of miR-223，HMGB-1 predicting sepsis were 0.904 (95%CI 0.821-0.998), 0.748 (95%CI: 0.625-0.903). There was positive correlation between miR-223 and HMGB-1 (r=3.532, P<0.05). Conclusions　The expression levels of plasma miR-223 in children with sepsis are significantly up-regulated, which can be used as early diagnostic markers to reflect the severity of inflammation in some degree.