Abstract： Objective This study was to investigate the association between serum Bisphenol-A (BPA) and unexplained recurrent spontaneous abortion (RSA).Methods A hospitalbased 1 ∶ 2 matched case-control study was conducted.Sixty-two patients with unexplained recurrent abortion were included and matched with 2 normal controls by factors as age ( ± 2 years),living in the same district and the same gestational age.The levels of BPA in serum for 62 cases and 108 controls were detected under high performance liquid chromatography after fluorescent derivatization.Levels of serum BPA in each case was compared with that in control of age,BMI,education levels,occupation,exposure for passive smoking.Results The values of serum BPA in cases and controls were ( 0.009 ± 0.002 ) and (0.004 ± 0.012) μg/ml,respectively.The levels of serum BPA in cases was significantly higher than in controls (Z=3.506,P=0.0005).After adjusted by age,BMI,education levels,occupation,passive smoking history and other factors,when compared to BPA below 0.004 μg/ml.The adjusted ORs were 4.39 (1.15-16.71)for BPA levels between 0.004 μg/ml and 0.012 μg/ml,and 4.95 (1.77-13.82) for BPA over 0.012 μg/ml.The risk of unexplained recurrentspontaneous abortion increased progressively with the growth of serum BPA levels (x2 =9.179,trend test P=0.0024).There were significant differences on BPA among controls that with histories of two,three or more abortions (the levels were 0.004,0.008,0.018 μ g/ml,respectively,F=8.92,P=0.0002).Conclusion High BPA level might be associated with unexplained recurrent spontaneous abortion.