Abstract: In this study, the toxicological effects of the different concentrations of heavy metal ions（Pb^2＋and Hg^2＋） on zebrafish were evaluated. The embryonic mortality rate and hatching rate, deformity rate of juvenile fish, and the activity of superoxide dismutase（SOD） and glutathione S-transferase（GST-S） in embryonic cells were determined. The results showed that when zebrafish was exposed to different concentration of Pb^2＋or Hg^2＋for 8 to 92 hours, the embryonic mortality rate in treatment groups for both heavy metal ions was found significantly increased compared to the control groups（P〈0.05）; the embryonic hatching rate exhibited a descending trend as the Pb^2＋concentration increased, and the deformity rate of juvenile fish was increased when exposed to higher Pb^2＋concentrations; no significant impacts of Hg^2＋exposure on embryonic hatching rate were observed（P〉0.05）, but 0.000 4 mg/L and 0.000 8 mg/L Hg^2＋treatment groups had significantly higher deformity rate of juvenile fish compared to 0.000 2 mg/L Hg^2＋treatment group（P〈0.05）; the different types of malformation were observed in both Pb^2＋and Hg^2＋exposed juvenile zebrafish; as the extension of exposure duration, the SOD activity in embryonic cells for Pb^2＋and Hg^2＋treatment groups exhibited a gradually descending trend（P〈0.05） and a gradually ascending trend（P〈0.05）, respectively; the GST-S activity was initially increased and then declined for both Pb^2＋and Hg^2＋treatment groups, and the greater changing range was observed in Hg^2＋treatment group. In conclusion, the heavy metal ions of Pb^2＋and Hg^2＋had toxicological effects on zebrafish embryo, and the mortality rate and hatching rate of embryo and the deformity rate of juvenile fish were affected by regulating the activity of antioxidant enzymes（SOD and GST-S）.