Abstract: Objective To explore the relationship between the single nucleotide polymorphism of interferon-gamma gene +874 site and breast cancer. Methods Using PCR technique to analyze the single nucleotide polymorphism (SNP)of Interferon-gamma Gene +874 site A/T of 96 normal women and 94 female breast cancer patients, the PCR products were cloned and sequenced. Results The frequency of interferon-gamma gene +874 site TT genotype was significantly higher in patients with breast cancer than that in the healthy individuals(18. 1 % vs 8. 3 %, P < 0. 05) ; T allele f requency was higher in breast cancer group than in normal group . But the TT genotype had no significant correlation with the age in breast cancer patient s. Conclusion 　TT genotype of IFN-γ+ 874 site might have a relationship with generation of breast cancer.