Abstract: Objective To investigate the association of Coxsackie B virus (CBV) with habitual abortion. Methods CBV IgM antibody, viral RNA and virions were detected in 86 women with habitual abortion and 40 with induced abortion by means of enzyme-linked immunosorbent assay (ELISA), RT-PCR and virus isolation, respectively. Results The positivity rate of CBV IgM were 87.2% and 35% in the two groups, respectively, and the detection rate of the viral RNA was 53.5% and 17.5% in blood lymphocytes, and 59.3% and 17.5% in the placentas. The virions were found in the placentas in 41.9% and 6.9% of the women, respectively. The positiivty rates of CBV IgM, viral DNA and virions showed significant difference between the two groups (P<0. 01). Conclusion CBV might be one of the causes responsible for habitual abortion.