The effect of sodium glycididazole (CMNa) on Zebrafish embryos was investigated. The wild-type Zebrafish eggs were placed in different concentrations of sodium glycididazole and received different doses of ,60,Co γ-rays irradiation. The morphological changes of embryonic development at different time and the survival rate were recorded at the 71 h. The repeat experiments and statistical analysis were further made. It was observed that the hatching rate of the normal form of the fish was 76%, 52%, 14% and 0% after exposure to γ-rays for 71 h with 0, 5, 10 and 15 Gy, respectively. And relative hatching rate was 40% and 0% after exposure to γ-rays with 5 and 10 Gy respectively when the samples treated with aqueous solution of 0.30 mmol/L CMNa. The radio-sensitive effects with treatment of 0.3 mmol/L CMNa was significantly higher than that in control (,p,<,0.01). Zebrafish eggs may be suitable for the study of radio-sensitive effect as a special model. And it should take more attention as CMNa has a significant radio-sensitive effect on Zebrafish embryos.