Abstrac Heavy metals are serious environmental problem in aquatic ecosystems due to rapid industrialization and technological advances. They make the toxicity, prolonged persistence, and bioaccumulation in food chains around the world. The heavy metals destroy the planktonic species in ecosystems or could be transmmited to higher trophic levels by food chains that impact the human health. Lead (Pb) and cadmium (Cd) are important pollutants in aquatic environments which have acute and chronic effects on aquatic consumers, especially water-flea (cladocerans). In this study, effects of different concentrations of Pb (0, 0.015, 0.100, 0.200, 0.300, 0.400 mg/l) and Cd (0, 0.001, 0.005, 0.015, 0.020, 0.025 mg/l) for Daphnia magna and Pb (0, 0.008, 0.064, 0.120, 0.180, 0.250 mg/l) and Cd (0, 0.0005, 0.005, 0.010, 0.015, 0.020 mg/l) for Ceriodaphniaquadrangula were investigated as compeletely randomize design with three replications at laboratory conditions. In this research, population dynamic, specific growth rate, the rate of Pb and Cd absorption and their bioaccumulations were measured at adults and neonates during 14-days culture period. The results showed that different concentrations of Pb and Cd had significant effects (p 0.05) on population density and specific growth rate in both examined species, except Cd on D. magna . The density and SGR of population ranged 40 to 86 individuals/vials and 3 to 5 /day, respectively for C. quadrangula exposed to Pb, correspondingly, these amounts ranged 18 to 73 ind./vial and 3 to 5 /day for D. magna .The density and SGR of population ranged 33 to 3 ind./vial and 1 to 4 /day, respectively for C. quadrangula exposed to Cd, correspondingly, these amounts ranged 30 to 53 ind./vial and 3 to 4 /day for D. magna . The Pb and Cd concentrations in C. quadrangula adults ranged 0 to 0.3 and 0 to 0.4 mg/g, while for neonates ranged 0.24 to 0.45, and 0.04 to 0.22 mg/g, respectively. Correspondigly, for D. magna were 0.03 to 0.5 and 0.07 to 0.2 mg/g for adults and also were 0 to 0.36 and 0.03 to 0.09 mg/g for neonats, respectively. The concentrant Pb was higher in C. quadrangula and D. magna compared to Cd. The amount of Pb was higher in C. quadrangula than in D. magna. The biological accumulation factor (BAF)showed that Cd accumulation was higher than Pb. In general, the finding of this study showed that Pb and Cd decreased the growth and reproductive prameters and increased their concentration in adult and neonate of cladocerans. Keywords :Cladocerancs,Bioaccumulation, Lead, Cadmium, Scenedesmus quadricauda