In this research, the effects of different levels of prebiotic Immunogen on reproductive performance of angelfish (Pterophyllum scalare) were investigated. 16 pairs of angelfish breeders with average weight 8.67±033 were fed till saturating for 50 days and after this period, reproductive indices such as absolute fecundity, hatching percent, larval survival until yolk-sac absorption, gonadosomatic index and larval tolerance against high temperature stress to amount 10 °C were evaluated. The experiment was carried out in completely randomize design with four levels 0 (control), 1% (T1), 1.5% (T2) and 2% (T3) that each treatment had 3 replications.  Amount of absolute fecundity in T2 significantly was higher than control (p<0.05), but there were no significant differences among T1, T2, T3 and between control with T1, T3 (p>0.05). Gonadosomatic index in T2 and T3 was upper than control and T1 that this difference was significant (p<0.05). The highest hatching percent was observed in T2 (75±9.28) and T3 (66.95±8.85), respectively, so that significant differences (p<0.05) was seen among T2 with control and T1. In addition, there were no remarkable differences in larval survival until yolk-sac absorption and larval tolerance against thermal stress (p>0.05). Regarding to findings of this research, addition prebiotic Immunogen at level of 1.5% to angelfish breeders' diet was recommended for reproductive indices promotion.