Objective To establish the polymorphism of DXS102 locus from Xq26.3-27.1 in Chinese population for the gene diagnosis in Hemophilia B family.Methods DNA was extracted from blood samples obtained from Shanghai unrelated volunteer donors with phenol-chloroform method. A total of 23 × chromosomes (154 from females, 80 from males) were studied. A hemophilia B family in which a hemophilia B patient has received gene therapy was analyzed. The polymorphism of DXS102 locus in Chinese population was determined with amplified fragment length polymorphisms assay (Amp-FLP), denaturing polyacrylamide gel electrophoresis, silver stain detection. Short tandem repeats (STRs) linkage analysis was used to conduct gene diagnosis in hemophilia B family.Results Eight alleles were found at DXS102 locus, of which two alleles were first reported. The repeated number of AC dinucleotide ranges from 13 to 21. And the values of the observed heterozygosity, calculated heterozygosity and polymorphism information content(PIC) were 0.87, 0.80, 0.80 respectively. It was also found that the difference of the allele frequencies of DXS102 in Chinese and European populations was significant. By using the linkage analysis of the DXS102 locus, a family with a hemophilia B patient receiving gene therapy in 1994 was analyzed and meanwhile a carrier in that family was then detected.Conclusions The polymorphism of DXS102 locus reveals significant difference between Chinese and European populations. DXS102 locus can be used as a promising marker for gene diagnosis in hemophilia B family.