he effects of main environmental factors(temperature，salinity)on energy utilization efficiency and energy budget of Macrobrachium nipponensis feeding on Bellamya sp. were studied by means of experimental ecological methodoligies. An equation of energy budget of M. nipponensis feeding on Bellamya sp. was established. The results indicated that the energy used for assimilation and growth accounted for 80. 7%and 34. 7% of total energy consumption respectively. It demonstrated that Bellamya sp. meat was anexcellent natural diet for the shrimps. The meat with high energy can be easily digested and absorbed by the shrimps. The study also indicated that expenditure of metabolic and excretion energy would be minimized when water temperature is 25 `C and salinity，3%0. The paper also reported the effect of rate of feeding and body weight of M. nipponensis on its specific dynamic action (SDA)and proposed that the studies on the bioenergetics is an effective way to improve the culture yield and economic efficiency of famous and special reared species.