Abstract： A nested PCR sequence specific primer (PCR-SSP) method was developed to be used in HLA-DR genotyping. A pair of primers was used to amplify a 283bp fragment of HLA-DRB1 exon 2, then 11 pairs of group-specific primers were utilized to amplify the corresponding fragments by which HLA-DR specificities were determined. A total of 20 DNA samples from patients were analyzed for HLA matching before bone marrow transplantation by both serological and genetic methods. The results indicated that the same types were identified in 80%, different types in 20% by the two methods. In the 20 DNA samples, 7 kinds of types: DR2, DR3-6, DR4,DR7, DR9, DR11, DR12 were amplified.