Abstract: OBJECTIVE To investigate the relationship between the expression levels of high mobility group protein B1 (HMGB1) in hepatic tissue with severity and prognosis of sepsis in patients. METHODS The sepsis patients from Apr. 2014 to Jun. 2015 in our hospital for treatment were analyzed, and divided into sepsis group(27 cases) and severe sepsis group(28 cases), and the control group had 31 cases. Clinical serum HMGB1 levels within 24 hours and within 21 days of prognosis were collected, and their expressions were determined by enzyme-linked immunosorbent assay. RESULTS Through the clinical examination, serum HMGB1 levels within 24 hours of onset of control group, sepsis group and severe sepsis group were (43.7±17.5) μg /L,(82.9±24.8)μg/L, (145.9±31.4) μg /L, respectively, which had significant differences (P<0.05). The plasma HMGB1 level of non-survival group of prognosis was significantly higher than that of the survival group. CONCLUSION HMGB1 expression in patients with sepsis was significantly increased within 24 hours of onset, and its expression of prognosis indicated the severity of sepsis, and was highly correlated with patient's prognosis.