ObjectiveTo investigate the relationship between the polymorphisms of estrogen receptor α (ERα) gene PvuⅡ, XbaⅠ and breast hyperplasia. MethodsPolymerase chain reaction-restriction fragment length polymorphism was used to detect the polymorphisms of ERα gene PvuⅡ, XbaⅠ in breast hyperplasia patients (study group, n=89) and healthy controls (control group, n=35). ResultsThe differences of the genotypic frequency and allele frequency of the ERα gene Xba Ⅰ were significant between the study group and the control group (Plt;0.05). According to analysis of the odds ratio (OR), the risk of developing breast hyperplasia for X allele carriers was 0.551 as compared with x allele carriers. But there was no significant difference for the gene polymorphism of PvuⅡ between the study group and the control group (Pgt;0.05). ConclusionThe polymorphisms of XbaⅠof ERα gene is associated with breast hyperplasia and the mutant gene increases breast hyperplasia risk.