Abstract： Objective To investigate the relationship between the expression of triggering receptor1 present on myeloid cells ( TREM-1 ) in intestinal tissue and intestinal barrier dysfunction in severe acute pancreatitis (SAP). Methods Sixty-four male Wistar rats were randomly (random number) divided into sham operation group ( SO group, n = 32) and SAP group ( n = 32 ). The SAP model was established by retrograde injection of 5％ sodium deoxycholate into bile-pancreatic duct. Specimens from blood and intestinal tissue were collected 2, 6, 12 and 48 hours after modeling. The levels of D-lactate, diamine oxidase (DAO) and endotoxin in serum were measured with an modified spectro-photometric method. The expressions of TREM-1, IL-1β and TNF-αt mRNA in terminal ileum were detected by RT-PCR. All data were processed with SPSS version 16. 0 package to make one-way ANOVA and Spearman correlation analysis. Results The serum levels of D-lactate, DAO and endotoxin were significantly increased at all intervals in SAP group compared with SO group ( P ＜ 0. 05 ). The expressions of TREM-1, IL-1β and TNF-α mRNA in terminal ileum of rats in SAP group at all intervals were significantly higher than those in SO group (P ＜ 0. 05 ). The expression of TREM-1 mRNA was positively correlated with expressions of IL-1 β and TNF-α mRNA ( r = 0. 956, P = 0. 044; r = 0. 986, P = 0. 015 ), but correlation was not found between expressions of IL-1β mRNA and TNF-α mRNA ( P = 0. 133 ). Conclusions The expression of TREM-1mRNA in intestinal tissue of rats with SAP is elevated, leading to the release of inflammatory cytokines and intestinal mucosal injury, indicating TREM-1 might play an important role in the genesis of intestinal barrier dysfunction in rats with SAP.