To detect the frequency of Toll-like receptor (TLR) 4896A>G (Asp299Gly) polymorphism in acute pancreatitis (AP) patients and to determine the relationship between polymorphism and pancreatic necrotic infection.The allele frequency of TLR4 Asp299Gly was surveyed by mispairing polymerase chain reaction-restriction fragment length polymorphism analysis technique in AP patients with pancreatic necrosis and healthy volunteers, respectively.All individuals with TLR4 Asp299Gly polymorphism were heterozygotes. Compared with healthy volunteers (5.6%), TLR4 896G allele frequencies was significantly higher in AP patients with pancreatic infection (20%), the incidence of gram-negative infection was significantly higher in AP patients with TLR4 Asp299Gly polymorphism (15 [44%]/34) than that in AP patients without TLR4 polymorphism (15 [18%]/81).Toll-like receptor 4 Asp299Gly polymorphism is associated with the infection of pancreatic necrosis in AP. Patients who carried TLR4 896A>G mutation is susceptible to pancreatic gram-negative bacteria infection.