Objective To study the protective effect of δ opioid receptor agonist DADLE(D-Ala2-D-Leu5-enkephalin)on mitochondrial respiratory function in a rat model of sepsis. Methods Sixty SD rats were randomly divided in to sham operated group (SO), septic group (SEP), and DADLE group (DADLE), each of 20 cases. Sepsis model was produced by cecal ligation and puncture (CLP). In SO group,the abdomen was opened without any other treatment. In DADLE group, DADLE (0.5 mg/mL) was administer at a dose of 5 mL/kg by intra-peritoneal injection after CLP. All rats were sacrificed 8 hours after CLP. ALT and AST in blood were determined. Mitochondrial respiratory function was evaluated by the clark oxygen eletrode. The levels of ATP, ADP, AMP were determined by high performance liquid chromatogra phy (HPLC). Results RCR and ADP/O in DADLE group were much higher than that in SEP group (P<0.05). ATP in DADLE groups were much higher than SEP group (P<0.05), while ALT and AST of DADLE group were significantly lower than SEP group (P<0.05). Conclusion DADLE can protect mitochondrial respiratory function and improve the hepatocellular energy metabolism in sepsis.