OBJECTIVE Interleukin-10 (IL-10) is a multifunctional cytokine with both immunosuppressive and antiangiogenic functions.Previous studies have reported that IL-10 levels are signifi cantly elevated in patients with gastric cancer (GC). It has also been confirmed that interindividual variations in IL-10 production are genetically attributed to the polymorphisms of IL-10 gene.Therefore, this study was designed to investigate whether the polymorphisms of IL-10 gene were associated with susceptibility to GC in the Chinese population.METHODS The serum levels of IL-10 were measured by radioimmunoassay. The single nucleotide polymorphisms (SNPs) at positions -1082A/G, -819T/C and -592A/C in the IL-10 gene promoter were analyzed using polymerase chain reactionrestriction fragment length polymorphism (PCR-RFLP).RESULTS 220 patients with gastric cancer and 180 healthy controls were included in this study. The serum levels of IL-10 were signifi cantly higher in GC patients than healthy controls (Z = -19.13, P < 0.001). Single SNP analysis showed that the -1082G allele, -1082AG and -819CC genotypes significantly increased in patients with GC (P = 0.029, 0.021, 0.039 respectively). In a logistic regression analysis adjusted for age and sex, the -1082AG genotype was associated with an odds ratio of 1.974 (95% CI,1.14-3.391; P = 0.014), and the -819CC genotype with an odds ratio of 2.496 (95% CI, 1.222-5.102; P = 0.012) for GC. Furthermore,haplotype analysis revealed that at least five haplotypes (ATA,ACC, GCC, ACA and ATC) were existent in this population.Also that the GCC haplotype was associated with a signifi cantly increased risk of GC as compared with the ATA haplotype (OR =1.90; 95% CI, 1.11-3.27; P = 0.02).CONCLUSION The results indicate that the gene haplotype of IL-10 may contribute to the susceptibility to GC in the Chinese population.