Abstract: In recent years, organic phosphorus flame retardants (OPFRs), widely detected in various environmental media, have become a new type of pollutants of great concern. An experiment was designed to explore acute and chronic toxicity of triphenyl phosphate (TPhP), tri-n-butyl phosphate (TnBP), tris(dichloropropyl)phosphate (TDCPP), and tris(chloropropyl)phosphate (TCPP) to zebrafish embryos. Hatching rate, survival rate, heart rate, body length, abnormal rate and mortality of zebrafish embryos were measured in the study. On such a basis, preliminary risk assessment of these OPFRs were performed in the light of their detections in some surface waters reported in literature. Results show that TPhP, TnBP, TDCPP and TCPP to zebrafish embryos reached 1.90, 2.27, 2.32 and 14.1 mg·L^-1, respectively, in 96 h-LC₅₀ and 0.03, 0.05, 0.05 and 1.00 mg·L^-1, respectively, in 32 d-NOEC of chronic toxicity. Hatching rate, survival rate, heart rate, as well as body length was negatively related to concentrations of the test substances, while abnormal rate was positively related. Environmental risks of TPhP, TnBP, TDCPP and TCPP varied in some important waters in China. In some waters, RQ values of the OPFRs were greater than 0.1 or even 1, indicating that their environmental risks are in the range from medium to high, which calls for adequate attention.