Abstract: The acute toxicities and species sensitivity distributions (SSD) of four hazardous chemicals, p-chloroaniline, 1,2-dichloroethane, butyl benzyl phthalate and 1-phenylethyl alcohol, on Chlamys farreri and Ruditapes philippinarum were investigated in the present study. The results showed that the 96 h lethal concentration 50% (LC₅₀) values of p-chloroaniline, 1,2-dichloroethane, butylbenzyl phthalate and 1-phenylethanol to C. farreri were 36.18, >2070.00, 123.16 and 180.89 mg/L, meanwhile,96 h-LC₅₀ values to R. philippinarum were 122.61, >2070.00, >2010.00 and 639.31 mg/L, respectively, C. farreri were more sensitive to four dangerous chemicals than R. philippinarum. Based on the SSD models, the short-term toxicity thresholds of butyl phthalate, p-chloroaniline and 1,2-dichloroethane were 0.64, 2.04 and 37.20 mg/L. The research would provide a theoretical basis for ecological risk assessment and pollution control of four hazardous chemicals in the marine environment.