The aim of this project is to cultivate and confirm the sex ratio of the progeny of masculized grey mullet parent to determine whether the male parent is a neomale or not. In addition, the experiments of masculinization of the offspring and female grey mullet are carried out. Up to now, the gonads of the third and fourth batch of offspring are still ovarian performance, and the offspring may be all female. Therefore, it is estimated that the male parent fish may be a neomale. In the remaining batches of offspring, the proportion of male fish is very high, ranging from 51% to 95%. It is estimated that the parent fish is not a neomale. In the masculinization of mullet offspring, methyltestosterone can be 100% effective. In addition, long-term feeding of methyltestosterone feed (100 mg/kg fed)can promote ovarian to testis and the optimal concentration of methyltestosterone should be explored to improve the male ratio and spermatogenesis.