To study the correlation between chromosome centromeric dots and habitual abortions, Cd variation, Cd loss,maximum diameter of Cd and Cd-NOR of 38 habitual abortion patients and 42 healthy persons were measured, compared and analysed with Cd-banding technique. It was found that the frequencies of Cd variation and Cd loss were obviously higher and maximum diameter of Cd was smaller in habitual abortion patients than those in healthy persons. The increase of frequencies of Cd variation and Cd loss and the decrease of maximum diameter of Cd might be the causes affecting habitual abortions.