Objective:To study the effects of polychlorinated biphenyls(PCBs) on the development of zebrafish embryo. Methods: We studied the influences of different concentrations (3.000, 2.000, 1.000, 0.500, 0.250, 0.125, 0.050 mg/L) of PCB1254 on morphological development, mortality rate and percentage of hatching using zebrafish as the model animal. Results: ①PCB1254 got teratogenic and mortality effect on zebrafish both at high and moderate concentration (above 0.25 mg/L). With the concentration increasing, hatching rate of zebrafish egg decreased while the mortality rate and the teratogenic rate risd obviously, which indicated that there was an obvious dose-depending effect; ②Deformities of zebrafish embryo exposed to PCB1254 mainly manifested spinal curvature and pericardialites; ③No effect was observed with the concentration of PCB1254 below 0.125 mg/L on the zebrafish; ④The 96 h LC50 of PCB1254 on the zebrafish was 1.082 mg/L, with 95% confidence interval ranging from 0.917 to 1.327 mg/L. Conclusion:Teratogenic and mortality effects are obersved on the development of zebrafish embryo exposed to different concentrations of PCB1254, which suggests the value of monitoring organic contaminant.