Abstract: Histological observations revealed that ovoviviparous teleost,Sebastiscus marmoratus ovaries consisted of ovarian wall,villi ovariales and ovarian cavity.The muscular layer of the ovarian wall was rather thick.The intraovarian epithelium had secretory function.Villi ovariales were in the ovarian cavity with the shape of tree crown.There were follicles in the villi ovariales.A follicle was made of an oocyte and follicular envelope,which consists of an inner layer,granulosa layer and an outer layer,thecal layer.The thecal layer was rich in capillaries.At each side of the follicle there was a stalk of follicle.The two stalks enabled the follicle to be hanged over the villi ovariales.Ovarian development could be divided into 7 stages.Mature eggs were discharged into the ovarian cavity and were fertilized there.Embryos would develop in the ovarian juice.The ovarian development,the coefficient of maturation in the ovary and the thickness of ovarian wall all showed annual changes.