Objective To explore effects of sulfentanyl preconditioning on myocardial injury in scald in diabetic and non-diabetic rats.Methods Eighty SD rats (40 diabetic rats and 40 non-diabetic rats)were divided into eight groups (10 rats per each),including sham group(group NS,non-diabetic rats with sham burn),burned group(group NB,non-diabetic rats with third-degree burns over 30%total body surface area (TBSA)and lactated Ringer??s solution for resuscitation),sulfentanyl group (group NP,non-diabetic rats without given sulfentanyl before burning and lactated Ringer??s solution for resuscitation)and naloxone group(group NN,non-diabetic rats given naloxone before sulfentanyl group),Diabetes sham group(group DS,diabetic rats with sham burn),Diabetic rats burned group (group DB,diabetic rats given third-degree burns,over 30 percent of the total body surface area had been burned and given lactated Ringer??s solution for resuscitation),diabetic sulfentanyl group(group DP,diabetic rats given sulfentanyl before burning and given lactated Ringer??s solution for resuscita-tion)and diabetic naloxone group(group DN,diabetic rats given naloxone,after that treated as the sulfentanyl group).Results Compared to group NB,for the mice in group NP,the activity of plasma SOD increased significantly,TNF-α,cTnI and water content level in myocardium decreased signifi-cantly (P <0.05 );whereas TNF-α,cTnI and water content level in myocardium in group DB in-creased significantly (P <0.05);Compared to group DB,for the mice in group DP,the activity of plasma SOD increased significantly,MDA,TNF-α,cTnI and water content level in myocardium de-creased significantly (P <0.05).Conclusion Diabetes may deteriorate burn-induced myocardial injury in rats.Sulfentanyl pretreatment exhibits significant protective effects on burned-induced myocardial injury in severely burned diabetic rats via inhibiting lipid peroxidation and TNF-αexpression.