Sulfuric derivatives are potentially hazardous to human health, especially during embryogenesis. Zebrafish were used to study the toxic effect of sodium thiosulfate (STS) (1~1 x 10(-6) mol/L) on embryo development with real-time in vivo imaging. Motor neuron differentiation and proliferation were analyzed by detecting the dynamics of acetylated tubulin (alpha-tubulin) and of proliferating cell nuclear antigen (PCNA). The expression pattern of brain- and muscle-specific microRNAs was detected by whole-mount in situ hybridization. The development of embryos exposed to 0.1~1 mol/L STS was severely retarded and was accompanied by malformation of multiple organs; embryos exposed to 10 micromol/L~10 mmol/L STS had circulatory, nervous and maxillofacial malformations. Embryos were more sensitive to STS at 48 hours post fertilization (hpf) compared with 24 and 96 hpf. STS can destroy the normal development of motor neurons and can affect cell proliferation. We also found differential expression of miR-124a and miR-133a in STS-treated embryos. STS interferes with the normal cytoskeleton structure, inhibits cell proliferation and leads to nervous, cardiac and maxillofacial malformations. MiR-124a and miR-133a were involved in STS malformation induction.