To establish the method for prenatal sex diagnosis of the fetus carrying sex-linked genetic disorder.Human SRY gene was amplified by polymerase chain reaction. A 422-bp male specific fragment was obtained.The fragment was identified in 10 men, but unidentified in 10 women. The diagnostic accordance rate of 20 amniotic fluid samples was 100%, 22 of 47 chorionic villi samples were positive. The rate of positive/negative (22/25) was nearly the sex rate of newborn babies. In the meantime, direct-PCR amplification of blood and amniotic fluid was completed. The fragment was shown from 4 microliters to 0.5 microliters of blood and from 2 ml to 0.5 ml of amniotic fluid.The results show that fetal sex determination by PCR will be suitable for clinical prenatal diagnosis of sex-linked genetic disorders.