Abstract: Rhesus monkeys were injected 11-T or were performed with unilateral cryptochidism to induce decrease of sperm count and motility.The expressions of tPA,uPA and PAI-1 mRNA in the normal and treated caput,corpus and cauda epididymis,prostate gland and seminal vesicle were examined by in situ hybridization.Results showed that after 9 weeks of 11-T injection,tPA mRNA expression increased in corpus,decreased in caput,seminal vesicle and prostate,while kept consistant in cauda;uPA mRNA expression increased in seminal vesical,decreased in caput,corpus and prostate,but remained unchanged in cauda;PAI-1 mRNA expression increased in prostate,decreased in caput,corpus and seminal vesicle,and no significant change was found in cauda.Unilateral cryptorchidism did not markedly alter the expressions for tPA,uPA and PAI-1 mRNA.These results suggest that 1)uPA produced by caput and corpus epididymis may be involved in the acquirement of sperm progressive motility;2)testosterone,but not other factors from testis or temperature regulate the tPA,uPA and PAI-1 mRNA expressions in caput,corpus epididymis,prostate and seminal vesical in a regionspecific manner.However,the expressions for tPA,uPA and PAI-1 mRNA in cauda epididymis are regulated by none of the above factors.