For those pregnant women with an abnormal pregnancy history, the polymerase chain reaction (PCR) technique was adopted to screening the serum toxoplasmosis DNA (TOX-DNA). Then tests were made for further evidence of TOX-DNA in the amnionic fluids TOX-DNA was examined in cases with blood TOX-DNA positive. Gamma glutamyl transpeptidase (GGT) and alpha-fetoprotein (AFP) in the amnionic fluids were measured for reference, a antenatal diagnosis of the fetal congenital toxoplasmosis infection could thus be made. In the present paper, 9 out of 92 blood specimen were TOX-DNA positive, of the 9 cases, 5 had TOX-DNA and 4 had no TOX-DNA in the amnionic fluid tests. The results of follow-up examination in the 9 cases were in conformity with the ante natal diagnosis. This is an important procedure for diagnosis and prevention of maternal-fetal vertical infection of Toxoplasmosis.