The experiments of predation of Leptodora kindti on two common cladoceras, Diaphanosoma brachyurum and Moina micrura were carried out in Donghu Lake. Predation rate coefficients (Clearance rates) were 15.9 mL predator^-1day^-1 at 17℃,18.2 mL predator^-1day^-1 at 21℃ on Diaphanosoma brachyurum respectively, K-value was increased with temperature. Predation rate coefficient was 30.1 ml predator^-1day^-1 at 17℃ on Moina micrura. K-value of Leptodora kindti on Moina micrura was much higher than that of on Diaphanosoma brachyurum. The experimental volum (density of prey) also affected predation rate coefficients. The bigger the experimental volum,the higher the K-value.Energy flow dynamics of Leptodora kindti in plankton community in Donghu Lake were also studied. Energy of predation of Leptodora kindti on micro-cladoceras was 2.5 J m^-3day^-1 in Donghu Lake.The relationships between predation of Leptodora kindti and population change dynamics of micro-cladoceras were discussed.