The present paper describes the histology and annual changes in the ovaries of Trichiurus haumela (Forskal) from the East China Sea.The ovary cycle can be divided into the eight stages according to histological composition and various features such as general appearance, colour, size and weight of the ovary, ovadiameter, and spawning activity. Yolk formation in the oocytes becomes active in early winter. Oocytes of the oldest generation in which the ovum matures appear in April. The weight and volume of the...