To observe the changes in plasma endotoxin level and lipopolysaccharide binding protein (LBP)/lipopolysaccharide receptor CD14 gene expression in the postburn Staphylococcus aureus infection, and to investigate their potential role in the pathogenesis of sepsis. 70 Wistar rats were divided randomly into three groups: normal control ( n =10), scald control ( n =10) and postburn sepsis group ( n =50). In the postburn sepsis group, rats were subjected to 20% TBSA Ⅲ?scald followed by Staphylococcus aureus challenge. LBP/CD14 and TNF ? mRNA expression in the liver, kidneys, lungs and heart were determined in all groups. Plasma endotoxin level and intestinal diamine oxidase (DAO) activity were also measured. The results showed that, after thermal injury combined with Staphylococcus aureus infection, intestinal DAO activity significantly declined,measuring 219 3, 157 3, 182 3, 167 3 and 179 2 U/g protein at 0 5?2?6?12 and 24h, respectively, after Staphylococcus aureus administration (239 9 U/g protein in normal controls). Meanwhile plasma endotoxin levels was markedly elevated, peaking at 2 hours( P