DRB genes encode proteins that play an important role in the immune response, and their expressional regulation is crucial to the immune reaction. Sequence variation at the regulatory region can directly affect the gene expression level. The aim of the present study was to use Chinese samples to investigate the variation in the regulation region of the human leukocyte antigen (HLA)-DRB-expressed genes. Seventy- one single nucleotide polymorphisms (SNPs) were found in the four HLA-DRB-expressed genes. By comparing these data with SNPs in the U.S. National Center for Biotechnology Information dbSNP database, 69 SNPs (97.2%) were found to be novel. In addition, two genetic variations of insertion-deletion polymorphisms were discovered within the regulatory region of HLA-DRB1 gene. These polymorphisms can be used as resources of markers for association studies of complex diseases, for assessment of individual predisposition to diseases, and as research markers for population genetics and evolution.