To establish a non-invasive method for early prenatal sex determination of the fetus carrying sex- linkedgenetic disorder. The fetal specific fragment of Y chromosome was amplified by nested polymerase chain reactionfrom the preipheral maternal blood

and the results were compared with new born baby gender after parturition.The Y-specific sequence was identfied in 19 of 22 mothers given the male babies

positive rate was86.4%(19/22)

but unidentified in 22 mothers given the female babies. The result show that fetal sex deterinationby nested PCR will be (suitable) for clinical prenatal diagnosis of sex- linked genetic disorders.