Hemophila B is an X-linked bleeding disease, resulting from sequence alterations of the coagulant factor IX gene, Hemophilia B is caused by a variety of mutations, which can be found in the whole coding regions. We screened mutations of factor IX gene in 8 Korean hemophilia B patients. Amplifications of eight exons, promoter region, and their intron boundaries, were performed with polymerase chain reactions (PCRs) and the PCR products were analyzed by single strand conformation polymorphism (SSCP) with Phast System^(TM) employing silver staining protocol. PCR-SSCP is a powerful technique that can be used to detect base subsitutions. Now this technique was used expendingly for molecular biology and medical part. Here, we have detected six mutations of an altered migration pattern of single strand DNA. Each patients have different mutations in exon B, G and H. And now, we are identifying six different Hemophilia B mutations by direct sequencing.