Abstract: The acute and chronic toxicities of acrylamide are measured using Daphnia magna as test organism. The 24 h-LC₅₀and 48 h-LC₅₀ value of acrylamide to this species is 173.21 and 89.59 mg·L^-1,respectively. The results of 21 d life cycle test show that the reproduction of Daphnia magna is the most sensitive parameter of chronic toxicity to this chemical.The value of non-observed effect concentration（NOEC）on reproduction and the lowest observed effect concentration（LOEC）on reproduction of acrylamide to this species is 1.56 mg·L^-1 and 3.13 mg·L^-1,respectively.The maxium acceptable toxicant concentration（MATC）of acrylamide to Daphnia magna is 2.47 mg·L^-1,which is estimated on the basis of the above two values.