@@ Hemophilia A is an X-linked recessive hereditary hemorrhagic disease, with an incidence of 1/5000 males. Mutation of Anti-hemophilic globulin A (AHG) causes the disease, as a result of deficiency of FV1II for blood coagulation. The affected gene is located on Xq28, 186 kb in length. The disease presents genetic heterogeneity with more than 1,660 affected alleles identified so far.Although the FVIII replacement therapy is the most common approach used in clinic, the emergence of alloantibodies against FVIII (which inhibits the procoagulant activity) is beyond doubt. Lacking in effective cure, to detect the carrier and perform prenatal diagnosis of HA are vital to avoid the disease-caused allele transmission and cut down the morbidity of HA.