Redclaw crayfish (Cherax quadricarinatus) is a freshwater crayfish with high economic value, which entices fish farmers to farm and increases its production. Males of this species have larger harvest size than females, so it is proposed to culture an all-male population for increasing yields. This research aims to find out the effect of sea cucumber steroid extract and 17α-methyltestosterone at different temperatures on sex reversal of juvenile C. quadricarinatus. This research was designed using factorial complete random design method. The treatments were observed in controlled temperatures at 27 °C and 31 °C, with a dose of sea cucumber steroid extracts (SCSE) of 50 mg • kg −1 and 50 mg • kg −1 of 17α-methyltestosterone. The results indicated that both SCSE and 17α-methyltestosterone were most effective at 27 °C on increasing the male percentage of juvenile crayfish, which were up to 75.16 % and 73.79 % respectively. These steroid hormones had a significant effect on decreasing the number of female individuals and also on increasing total length, daily weight gain, and growth of juvenile crayfish. However, they did not make a significant effect on survival rate, the percentage of intersex and feed conversion ratio of juvenile freshwater crayfish.