Abstract: This study aimed to investigate the development and genetic toxicity of γ-ray to aquatic organisms by using the zebrafish, a model organism, as the object of study. Different cumulative doses (0.01-1.00 Gy) of γ-ray from γ cell irradiation apparatus were used to irradiate zebrafish embryos at 5 hpf. The survival, hatching, malformation rates and DNA damages of the zebrafish embryos, and the reproductive capacities and the activities of superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR) and peroxidase (GPx) in their liver, kidney and spleen of the adult fishes at 150 dpf developed from the irradiated embryos were analyzed, respectively. The results indicate that the irradiation of γ-ray with 0.01 Gy has no significant effect on the survival rates and hatching rates of zebrafish embryos, but the malformation rates significantly increase. The survival rates and hatching rates of the zebrafish embryos significantly decrease when the cumulative doses of γ-ray irradiation are more than 0.10 Gy. After the zebrafish embryos at 5 hpf received 0.01 Gy γ-ray irradiation, the egg laying amounts produced by their adult fishes at 150 dpf significantly decrease in a dose dependent manner. The activities of CAT in liver significantly increase in the adult fishes at 150 dpf when the zebrafish embryos at 5 hpf are irradiated by 0.01 Gy γ-ray irradiation, indicating that it may be the potential biomarkers for assessing the toxicity of low dose γ-ray irradiation.