Aim: To evaluate whether estrogen receptor α (ER-α) and vitamin D receptor (VDR) genes are associated with the age at menarche in Chinese women.Methods:A total of 390 pre-menopausal Chinese women were genotyped at the ER-α PvuⅡ,XbaⅠ, and VDR ApaⅠ loci using polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP).Results: Neither the ER-α gene nor the VDR gene individually had significant effects on the age at menarche in our subjects (P＞0.10).However, evidence of interaction effects between the two genes were observed: with the aa genotype at the VDR ApaⅠ locus, subjects with haplotype PX at the ER-α gene had, on average, 6 months later onset of menarche than the non-carriers (P=0.01).Conclusion: We found that neither the ER-α gene or the VDR gene had a significant association with the age at menarche individually.However, potential interaction effects between the two genes were observed in Chinese women.