Serological typing for HLA-A, -B has been used for a long time. Recently with the developing of molecular biology technologies, HLA-A, -B typing is now turning to genotyping methods. In our study, the capacity of PCR-SSP in solving problems in HLA-A, -B typing with serological methes was evaluated. With this aim the serological method was compared with PCR-SSP in 102 cord blood samples, and the results showed that 18.6% of 102 cord blood samples can't give a satisfactory detection, for 14 samples, give discrepant results with the 2 methods. It is mainly due to weak expression of HLA class I cord blood lymphocytes and the cross reaction of some antigens. About B 15 group, the further study was made, it was found that most of the B 15 splits is wrongly disassigned, especially among the B62-B75, B75/*1511(+)-B75/*1511(-), B46-*1511 antigens. It was concluded that DNA typing is more preferable than serological typing, about B 15 group, the subtyping or high resolution typing can be fulfilled at first in China.