The morphological structure of female reproductive system of Octopus tankahkeei was investigated from August,2002 to December,2003. The female reproductive system of O.tankahkeei, like many cephalopods,is composed of three parts morphologically: ovary,oviduct,and oviducal gland.The ovary is a single structure,which contains oocytes at different stages.The oocytes are surrounded by a layer of columnar follicle cells which enfold into the oocyte cytoplasm and their nuclei are arranged along the longitudinal axis of the cells.Different from proximal oviduct,mushroom-like protruding enwrapped by many finger-like folds lies in the distal oviduct.The oviducal gland can be divided into three parts: central lumen,spermathecaes,and gland tissue.The twenty-four spermathecaes are special parts in oviduct gland which contain spermatozoa after coupling.We propose to divide the ovarian cycle of O.tankahkeei into four phases: previtellogenesis,early vitellogenesis,full vitellogenesis,and late vitellogenesis phases.