Objective:To evaluate the impact of the single nucleotide polymorphism (SNP) in Janus kinase 2(JAK2) rs1887427 on gastric cancer risk. Methods:In this hospital-based,case-control study,the genotypes were identified by polymerase chain reaction-restriction fragment length polymorphism protocols. Results:The frequencies of the wild and variant genotypes in cases were significantly different from those of controls (P = 0.027). Compared with individuals with the wild genotype AA,subjects with the variant genotypes (AG + GG) had a significantly higher risk of gastric cancer (P = 0.023,adjusted OR = 1.71,95% CI = 1.08-2.71). Moreover,in stratified analysis,the elevated gastric cancer risk was especially evident in younger individuals,males and nonsmokers (P < 0.05 for all). Conclusion:The JAK2 polymorphism is associated with an increased risk of gastric cancer in Chinese population.