In the elucidation of HLA-class I gene polymorphism, serological typing method has been replaced by genetic typing. We used a DNA-based tissue typing method for the determination of HLA-A alleles by PCR-SSP (polymerase chain reaction-sequence specific primers) and compared with serological typing. Genomic DNA prepared from lymphoblastoid 21 B-cell lines and lymphocytes from 44 Korean individuals by phenol/chloroform extractions have been typed by PCR-SSP DNA typing (32 primer mixes were used). The data of reference cells and 44 Korean samples using DNA typing were correlated well with serological typing. All combinations of serologically detectable samples and most of the serologically "blank" four HLA-A antigens could be completely typed by DNA typing. In conclusion, HLA DNA typing by PCR-SSP is more accurate than serological method for the determination of the HLA-A alleles. This technique is useful for the histocompatibility test in transplantation as well as the exact determination of mistyped allele by serological method.