This study was aimed to investigate the polymorphism of interleukin-1beta(IL-1B) and IL-1 receptor antagonist (IL-1RN) gene and the relationship between genotypes and development of gastric adenocarcinoma in Korean, and to investigate the role of Helicobacter pylori (H. pylori) infection.The study population comprised of 258 patients with gastric adenocarcinoma. They were classified according to Lauren's classification and the status of H. pylori infection. Genomic DNA was extracted from the gastric tissue. As a control, genomic DNA from peripheral lymphocyte of 100 healthy individuals was used. The amplified products of -511 bp and -31 bp fragments in the IL-1B by PCR were digested by restriction enzyme and separated for RFLP. Variable number tandem repeats were amplified and subjected to RFLP of IL-1RN.There was no significant difference in the genotype of IL-1B-511T and IL-1B-31C between the adenocarcinoma group and the control group. IL-1RN allele 1 homozygote in the intestinal type showed high frequency of 91.7% (p=0.007). In the H. pylori-positive group of the adenocarcinoma, the frequency of IL-1B-31C was significantly higher than that of H. pylori-negative group (p=0.045).The single nucleotide polymorphism of IL-1B-31C may contribute to the development of the gastric adenocarcinoma in the H. pylori-positive population.