Abstract: Objective: To detect existence and cytological location of hepatitis B virus(HBV) DNA in testis and epididymis of patients with positive HBsAg and HBeAg.Methods: The testis and epididymis tissues form 22 male patients with positive HBsAg and HBeAg and 18 normal male subjects were collected,and HBV DNA was detected from the tissues by nest PCR,fluorescence in situ hybridization(FISH) was used to identify the localization of HBV DNA.Results: HBV DNA were detected in the testis and epididymis tissues of 18 male patients with positive HBsAg and HBeAg,and the positive rate was 81.8%,whereas in normal group there was no HBV DNA detected,there was significant difference between two groups(P<0.001).HBV DNA mostly located in the spermatogenic epithelium and sertoli cells of testis and epididymis tissues.Conclusions: There were HBV DNA in testis and epididymis tissues of human with HBV and HBV DNA located in all levels of spermatogenic cells.These results in this study provide morphologic evidence for HBV vertical transmission.