Abstract: The reproductive system of B.horsfieldi (Hope) is studied by means of comparative anatomy and scanning electron microscopy.The male internal reproductive organs are composed of testes,vasa deferentia,accessory glands and ductus ejaculatorius duplex.The male external genitalia is made up of tegen, median lobe and internal sac.It is locuted in the cloacal chamber comprising abdominal segment 8 and 9.The female internal reproductive organs consist of ovarioles,oviductus lateralis,oviductus communis.vagina. bursa copulatrix,spermatheca and spermathecal gland.The ovipositor comprises the modified abdominal segments 8 and 9,intersegmental membrane 8/9.The hemisternites of abdominal segment 9 form a Pair of velvulae.The gonostyli is located at the apex of valvula.Gonostyli and valvula have several types of sensory receptors. The structural features and functions of the internal,external reproductive organs and their histological originates are also discussed in this paper.