Abstract:As one of the most important marine ornamental fish, is a protogynous hermaphrodite with a natural sexual reversion. Under appropriate social conditions, a female fish can transform into a male fish spontaneously. It is an important prerequisite for artificial breeding to understand the process of its gonadal development and sexual reversion. In this paper, sexual reversion was induced by artificial pairing, and the process of sexual reversion and gonadal development were studied using morphological and histological methods. The results showed that the gonads of could be divided into three types:pure female with ovaries, pure male with testes, and ♀/♂ bisexual. The gonads differentiate into those of females with pure ovaries at first; then sexual reversion occurs in stage II ovaries. The ovaries of a large female fish stop developing and atrophy gradually occurs in stage II after pairing induction for 1-2 weeks by one big and one small pair. At the same time, male germ cells are gradually differentiated from the ovarian wall and the oviposition plate; and female and male germ cells coexist in the gonad, forming a bisexual gonad of the hermaphrodite stage. After three weeks of pairing induction, the bisexual gonad differentiates into early testes entirely, indicating that the female has completed sexual reversion and has become a functional male. After four weeks of pairing induction, the testes of sexually-reverted males and the ovaries of small females mature and start spawning and spermiation. The relationship between total length, body mass, and sexual reversion was also analyzed, and the process, characteristics, and possible induction mechanisms of sexual reversion have been discussed. The results will provide theoretical guidance for artificial breeding and sex control technologies in , and lay the necessary groundwork for further research on the mechanisms of gonadal development and sexual reversion in , and enrich our understanding of hermaphroditic coral fishes.