The effects of water temperature and body weight on feeding, growth, and energy budget were inevitable in the yellow catfish Pelteobagrus fulvidraco (Richardson, 1846), an important fish cultivated in China. This study explores the interaction of water temperature and body weight on both energy utilization strategy and energy conversion efficiency to promote further healthy culture of yellow catfish. Fish with body weights of 6g (Group S), 16g (Group M) and 35g (Group B) were reared in 15 circular glass steel cylinders 80cm in diameterx70cm in height (180L) at water temperatures of 21, 24, 27, 30 and 33 degrees C (3 replicates for each temperature) for 42days to investigate effects of water temperature and body weight on the feeding, growth, digestion and energy budget in yellow catfish. Results showed that the levels of dry matter, protein and energy in the body were significantly affected by water temperature (p<.05). Feeding, growth, feed conversion efficiency, digestion and energy allocation parameters were significantly related to both water temperature and body weight (p<.05). Yellow catfish had higher maximal food consumption (C-max), food intake rate, specific growth rate, food conversion efficiency, appear digestibility coefficient, and growth energy allocation (G) at 24-30 degrees C, and optimal growth at a water temperature of 27 degrees C. Two-factor analysis of variance revealed that there was reciprocation of both water temperature and body weight on the above parameters. At the optimal temperature of 27 degrees C, the value of energy for growth (G) was the highest, and the value of energy for feces (F) produced was the lowest. Yellow catfish with various body weights had energy budget equations of 100 A=63.70 R+36.30G in Group S, 100 A=62.54 R+37.46G in Group M, and 100 A=67.47 R+32.53G in Group B if the equations were described as percentage of the proportion of the assimilation energy. Therefore, the optimal temperature was 27 degrees C according to its feeding, growth and digestion.