OBJECTIVE: To study the cardiac and skeletal toxicity of retinoic acid (RA) in Danio rerio at early life stage. METHODS: Danio rerio embryos of 24 hours post fertilization (hpf) were used as toxicity model and were exposed under medium with various concentrations of RA (0.1, 1, 10, 25, 100 μmol/L). The morphology of embryos and larvae hearts were observed 24, 48 h after exposed. LC50 was calculated. Danio rerio larvae of 4 days post fertilization (dpf) were used as skeletal deformity model and were exposed with a series of RA at various concentration (0.1, 1, 10, 25, 50 μmol/L). They were sacrificed 5 d later, and then Danio rerio skeleton were fixed for staining with alizarin red. The microscopic was used to observe the difference of stained skeleton area. RESULTS: RA caused significant adverse effects on hatching capabilities of Danio rerio embryos, and the obvious malformation features were produced during the culture process. 1-100 μmol/L RA could cause heart malformation in Danio rerio embryos and larvae, and the main heart malformation characteristics included heart linearization, pericardial edema, yolksacedema, hemocytes accumulation incardiac region. 100 μmol/L RA could inhibit the hatching capabilities of Danio rerio embryos, and caused lethal effects on embryos and larvae. The LC50 were 36.44, 23.69 μmol/L after exposed for 24, 48 h. 0.1-50 μmol/L RA induced vertebral column sclerotization of Danio rerio embryos and larvae in advance, which was positively associated with the concentration of RA. CONCLUSIONS: RA can cause cardiac and skeletal toxicity in Danio rerio embryo and larvae, which is positively associated with the concentration of RA.