The present study was designed in order to clarify ultrastructural characteristies of the spermatogenetic process and to examine survival state of the spermatozoa introduced into the female reproductive tract after autumnal coitus in the Korean greater horseshoe bats(Rhinolophus ferrumeguinum korai). The general morphological characteristics of spermatogenesis were principally similar to those of the other mammalian species; acrosomal formation, flagellar formation, middle piece formation and concentration of the spermatozoan nucleus. The spermatozoa introduced into the vagina were found to be dead forming a vaginal plug, the opaque central core of which consisted of trapped dead spermatozoa. Some spermatozoa introduced into the uterus were observed to be phagocytized by the polymorphonuclear leucocytes infiltrated into the uterine glandular lumen. The oviductal epithelium, consisted of ciliated and secretory cells; the luminal surface of secretory cells were covered by a number of microvilli with well developed glycocalyx, suggesting a close relationship to nutrient (e.g. glycogen) supply for the spermatozoa during hibernation.