The preovulatory oocyte of blunt snout bream was surrounded by anouter thecal layer and an inner granulosa layer which were separated from each otherby a distinct basement membrane. The thecal layer composed of thecal cells andcollagen fibers. The thecal cells contained an abundance of microfilament. Thegranulosa layer consisted of special granulosa cells and granulosa cells. The specialgranulosa cells were characterized by the presence of numerous smooth endoplasmicreticulum and mitochondria with tubular cristae. The special granulosa cells showedcellular organelles characteristics of steroidogenesis. The granulosa cells containedwell developed rough endoplasmic reticulum and mitochondria with lamellar cristae.