Abstract: In this paper, the 48 h LC₅₀ values of Cu²⁺， Cd²⁺ and Cu²⁺+Cd²⁺(Cu²⁺-Cd²⁺=1:1) to Moina macrocopa were determined by acute toxicity tests, and the effects of different concentrations of Cu²⁺, Cd²⁺ and Cu²⁺+Cd²⁺ on the life table demography of M. macrocopa were studied by life table demography. The 48 h LC₅₀ of Cu²⁺, Cd²⁺ and Cu²⁺+Cd²⁺ to M. macrocopa was 0.106, 0.117 and 0.212 mg·L^-1, respectively, and the acute toxicity of Cu²⁺+Cd²⁺ mixture to M. macrocopa showed an antagonistic effect. Cu²⁺ had no significant effects on the life expectancy at hatching, gross reproductive rate, net reproductive rate, generation time, and intrinsic rate of population increase of M. macrocopa, whereas Cd²⁺ and Cu²⁺+Cd²⁺ had significant effects on the life expectancy at hatching, gross reproductive rate, net reproductive rate and generation time, but no significant effects on the intrinsic rate of population increase of M. macrocopa. Compared with the control, the 0.004 and 0.005 mg·L^-1 of Cd²⁺ and the 0.006-0.010 mg·L^-1 of Cu²⁺+Cd²⁺ decreased the life expectancy at hatching and the gross reproductive rate of M. macrocopa significantly, and the 0.004 and 0.005 mg·L^-1 of Cd²⁺ and the 0.008-0.010 mg·L^-1 of Cu²⁺+Cd²⁺ reduced the net reproductive rate and the generation time of M. macrocopa significantly. The chronic toxicity of Cu²⁺+Cd²⁺ mixture to M. macrocopa showed a synergistic effect. There existed significant doseeffect relationships between the concentrations of Cd²⁺ and Cu²⁺+Cd²⁺ and the life expectancy at hatching, gross reproductive rate, net reproductive rate, and generation time of M. macrocopa.