The ABO blood group antigens in the spermatozoa from 40 donors were studied using the indirect immunofluorescence method.Group A antigens in the spermatozoa from group A donors and group B antigens in the spermat- ozoa from group B donors were detected.Some of the spermatozoa from group AB donors carry the A antigens and others carry the B antigens.The spermatozoa from four ABO blood group donors all carry H antigens.The blood group antigens in the spermatozoa are inherent,not from the seminal plasma.The amount of ABO blood group antigens from different individuals was different and was independens of the secrete status and the amount of ABH substances in the secretor's seminal plasma.The ABO blood group antigens of spermatozoa were mainly distributing in the regions of spermat- ozoals neck and acrosome.

The sperm antigens were examined using the method of ELISA and specific monoclonal antiboby against human sperm.The results of ELISA method of 10 fresh seminal fluid samples and 15 seminal stains showed 100% positive rate. Even diluted the fresh seminal fluid to 10~6 times of seminal stains extract to 51?0~5 times,both were positive also.However,it was negtive for testing other specimens such as saliva stains,urine stains,colostrum stains,sweat stains, vaginal secretion stains and human seminal stains after vesoligation. The result certificate that using specific antibody to the sperm,the ELISA method is high sensitive and specific for the sperm antigen assay.