Selenium is an essential nutrient for physiological function, including immunity, Reproduction and nervous systems. This element as glutathione peroxidase enzyme cofactor, improve fish growth and propagation index via reducing of free radicals. In the present study, the effect of different levels of organic selenium were evaluated on some antioxidant indices, such as total antioxidant capacity (TAC) and malondialdehyde (MDA) and Reproduction indices including, gonadal development, histology evaluation, fertilization rate and survival of the treated fish larva. Adult goldfish were fed with 0 and 0/5 mg of organic selenium (Selplex) per kg food for 8 weeks, and HCG hormone was injected Intraperitoneally to induce the gonadal development in the treated broodstocks. Results showed that the TAC in blood serum treated with selenium broodstocks was increased and MDA levels were also significantly reduced. Histological studies showed selenium treated testicular tissue broodstocks, the level of mature spermatozoa are significantly higher than the control group and in the ovarian tissue, sexual maturation in the control group and treated group were in stage 2 and 5 respectively. In addition, rates of fertilization (%91/17), deformity (%8/45) and survival (%87) in the Selenium treatment compared to the control group showed significant improvement. Therefore, Significantly higher body weight, antioxidant function, gonadal development in the fish treated with 0.5 mg selenium were shown in compare to the control group, to which no organic selenium was fed.