oocyte, and analyzed the ovary annual variation and spawning pattern. Results showed that ovary development could be divided into six stages. The first stage: long and thread-shaped ovary had an average length of 25 mm and its oocytes were mainly primary oocytes. The second stage: ovary was cylindrical in shape with an average size of 40−50 mm. A color change in appearance from yellowish to red was noted, and the oocytes at phase accounted for more than 92 percent of the total. The third stage: the appearance of ovary changed from lighter red to blue. in length and extended gradually in the middle part. The , the oocytes at phase the ovary in cystoid shape with the maximal diameter of 482 mm and its color turned from blue to grey was invaded. By the time, enlarged eggs and ones in the terminal stage were visible. The oocytes mainly filled with oil globules were observed in the terminal stage of oocytes development, and the oocytes at phase accounted for more than 86 percent of the total. The fifth stage: the bulgy and soft ovary in green color occupied most space of abdomen and was filled with eggs. The diameter of the egg had increased to 750–900 mm. Polarization phenomena was observed in both yolk and protoplasm. By the time, oocyte diameter was Ⅱ.is from April to June. The ovary develops into phase by the middle of October, and stagnates in this phase until February of the following year and starts to develop in the late March. the females only spawn once in one spawning season, and individual ovary development is significant different, so spawning generally continues for a long time.