Pervious studies reported the inconsistent conclusions about the association between the three polymorphisms (rs1225404, rs7003146, and rs7903146) and breast cancer in different ethnicities, so we performed this study to confirm the effect of the TCF7L2 polymorphisms to BC risk, we genotyped all participants from a Chinese Han population in Northwest China for the three important SNPs, rs1225404, rs7003146, and rs7903146. The gene discussed is TCF7L2; the disease is breast carcinoma.