Clinical data and samples of blood for detecting CMV antibodies were obtained from 716 pregnant women of whom, 6.84% and 95.61% had CMV IgM and CMV IgG antibody, respectively. Statistic analysis showed that high positivity rates of CMV IgM antibody were correlated with lower socioeconomic status, first pregnancy at less than or equal to 22 or greater than or equal to 29 years of age, and history of abortion, especially natural abortion. In the pregnant women primary CMV infection rates were not uniform in those of different occupations. Positivity rates of CMV IgM antibody were higher in medical workers and peasants (P less than 0.05).