Objective To analyze the correlation between polymorphism of the BRCA2 gene rs206115 loci and sporadic breast cancer in Inner Mongolia. Methods We enrolled patients from the Affiliated Hospital of Inner Mongolia Medical University from December 2015 to December 2016 who underwent breast surgery and were confirmed by pathology, resulting in a total of 101 cases of primary sporadic breast cancer (case group) and benign breast diseases (control group). DNA was extracted from blood samples and analyzed using polymerase chain reaction (PCR) and direct sequencing methods for determining the BRCA2 gene rs206115 loci polymorphism. SPSS 17.0 was used for statistical analysis. Results In this experiment, regardless of whether the patients were Han or Mongolian, the rs206115 loci could be detected in 3 kinds of genotypes:AA, AG, and GG. The BRCA2 gene rs206115 locus gene polymorphism was not significantly different between the case and control groups (χ2=3.490, P = 0.175). The A allele frequency of the BRCA2 gene rs206115 loci in the case group was significantly increased compared to the control group (χ2=4.259, P = 0.039). Conclusion The A allele of rs206115 may be one of the susceptibility alleles in sporadic breast cancer in Mongolian and Han populations.