Abstract: 【Objective】To investigate the development of ovary and oocytes of Varicorhinus macrolepis, and the effect of sex hormone on development of ovary. 【Method】Anatomy, histology, histochemistry of the oocytes were studied and the changes of sexual steroid by Radioimmunoassay(RIA) in annual reproductive cycle were also studied in the study; 【Result】The results are as follows: (Ⅰ) from February to April, the ovary developed from phase Ⅳ to phase Ⅴ; (Ⅱ) from April to June, the ovary was in phase Ⅴ; (Ⅲ) from June to July, after the finish of ovulation, the ovary entered phase Ⅵ. (Ⅳ) in August, the ovary changed into phase Ⅱagain; (Ⅴ) from September to January next year, ovary was in Ⅲ period and spent cold in winter. The concentration of E2 went up to peak in March before ovulating (53.6 pg·ml-1 around), and began to drop to minimum point from April to September and maintained at low level until January, then began to rise to March. The concentration of 17α, 20β-DHP rose to the highest point in April, and maintained at high level to the end of ovulating. Then it decreased from July to November and maintained at low level until March of next year; 【Conclusion】The results indicated that Varicorhinus macrolepis is in a successive process, and spawning season only once a year. The modulation of E2 and 17α, 20β-DHP was sufficient to the oocytes development in Varicorhinus macrolepis.

Key words: Varicorhinus macrolepis, Ovary, Oocyte, Goandal steroid hormone