Abstract: The HLA-AB typing of human spermatozoa identified by two colour fluorescence technique is reported in three cases.with the acridine orange and the ethidium bromide as stains,the human spermatozoa affected by HLA-AB antibody appeared two distinct colour fluorescence: the orange-red indicated dead spermatozoa earring the relevant HLA-AB antigen and jade green living ones noncarrying the antigen. Applied to the identification in disputed paternity,the HLA-AB typ- ing of human spermatozoa as haploid would raise the nonfatherexclusion probability (NFEP) of the assaying system,and as well as raise the paternity index (PI) and the relative chance of paternity (RCP).