【Abstract】Objective To study the expression of cyclooxygenase-2 (COX-2) in hepatic inflammatory reaction of rats with sepsis, and to explore a new way of protecting hepatic cell. Methods Fifty-four Wistar rats were randomly divided into 3 groups: sham operation group, sepsis group and NS398 group. All rats were subjected to cecal ligation and puncture (CLP) or sham operation. RT-PCR was used to determine COX-2 mRNA expression, serum IL-6, TNF-α and IL-10 were determined by ELISA; and ALT and AST and liver pathological changes were determined in 3 groups and at different times (3, 6, 12 and 24 h) respectively. Results ①The expression of COX-2 mRNA of hepatic tissue was low in sham operation group. It obviously enhanced after CLP at 3 h and peaked at 6 h. High expressions were showed at 12 and 24 h. In NS398 group, it was lower than that of sepsis group at the same time, but higher than that of sham operation group. ②Serum ALT, AST and IL-6, TNF-α were increased in sepsis group than those of sham operation and NS398 group (P＜0.05)； Serum IL-10 was higher in NS398 group than that of sham operation and sepsis group (P＜0.05). ③Hepatic pathological injury extenuate after injected with NS398. Conclusion COX-2 may play an important role in hepatic injury with sepsis.