This study was aimed to investigate the suitability of FVIII gene BclI (intron 18)and HindIII (intron 19) site polymorphism for genetic diagnosis of patients with hemophilia A (HA) and their families, and for detection of carriers. The FVIII gene bclI (intron 18) and HindIII (intron 19) site polymorphism on the X chromosome of 8 patients with HA and 45 families members were detected by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), the pedigree of patients was drawn by means of PediDraw software online provided by China Genetic Counseling Network. The results indicated that combination detection of BclI and HindIII sites could provide the diagnosis information for 5 out of 8 HA families with diagnostic ratio of 62.57%, especially 2 HA families were accompanied by mutation of 2 sites. Besides, the definite diagnosis for 6 out of 11 suspicious carriers in 8 families could be made with diagnostic ratio of 54.5%. It is concluded that the combination detection of BclI and HindIII sites for analysis of HA patient family can elevate the diagnostic rate of HA patients and carriers.