Abstract: Objective: To investigate the HLA-A and -B allele polymorphisms in the umbilical cord blood of Shandong people. Methods: 5844 umbilical cord blood samples were drawn from the Shandong umbilical cord bank and determined by the polymerase chain reactionsequence specific oligonucleotide (PCR-SSO) method. Results: Twenty alleles at HLAA locus and fortysix alleles at HLAB locus were detected. Of the twenty HLAA alleles, the most prevalent five alleles were A*02(0.3041), A*11(0.1443), A*24(0.1434), A*30(0.0975) and A*33(0.0859), and the least prevalent alleles were A*34(0.0006), A*25(0.0005, A*66(0.0005), A*74(0.0004) and A*36(0.0001). Of the fortysix HLAB alleles, the most prevalent five alleles were B*13(0.1348), B*51(0.0713), B*62(0.0712), B*61（0.0676）and B*60(0.0642), and the least prevalent alleles were HLAB*77(0.0001), B*76(0.0002), B*47(0.0003), B*42（0.0003）and B*72(0.0004). Comparing the HLA-A and -B gene frequencies of Shandong umbilical cord blood samples with those of other Han Chinese, there were unique distribution features of the HLA-A and -B alleles among the populations studied from various regions with the same racial origin. The differences from various regions of the same race were fewer than those from different races. Conclusion: The HLA-A and -B alleles in Shandong umbilical cord blood have a rich polymorphism, which represents the distribution characters of the HLA-A and-B alleles in Shandong Hans. For a patient of northern Han Chinese it is easy to search for a HLA-A or -B matched cord blood donor from the Shandong umbilical cord blood bank. For a patient of southern Chinese it is possible to receive a transplant of cord blood stem cells matched with HLA-A or B from the Shandong umbilical cord blood bank.

Key words: Fetal blood, Antigens, CD, Polymorphism, sigle nucleotide