Abstract:In order to evaluate the toxicity of nano-tungsten carbide (nano-WC) in aquatic system, zebrafish embryos were used. Results showed that the low concentration of nano-WC (<2g/L) had no significant impact on the development and function of zebrafish. Under the higher concentration of nano-WC (3g/L), 31% embryos developed abnormally, 33% embryos died and 36% embryos were totally normal. Results showed that 24h was the most susceptive period for zebrafish embryos exposed to nano-WC compared with that of 5h and 30h. Removal of the chorion before the exposure attenuated the adverse impact of nano-WC on zebrafish embryos.