Abstract: The oxygen consumption and ammonia excretion rates of juvenile brook trout (Salvelinus fontinalus) under satiation and starvation were measured at
 different levels of water temperature ［(5.5±0.5) ℃、(8.5±0.5) ℃、(11.5±0.5) ℃、(14.5±0.5) ℃、(17.5±0.) ℃］,aimed to study the effects of water temperature and feeding on the respiratory metabolism of the fish. Under satiation, the oxygen consumption and ammonia excretion rates of juvenile S. fontinalus at the five temperature levels increased rapidly to the maximum, and then decreased gradually to the initial state. The regression equations of oxygen consumption rate (OR) and ammonia excretion rate (NR) to water temperature (t) wereOR=-0.0601t⁴+2.5542t³-39.256t²+276.26t-598.75(n=650，R²=1，4.5 ℃<t<17.5 ℃) and NR=-0.0020t⁴+0.0826t³-1.2318t²+8.6186t-18.838(n=650，R²=1，4.5 ℃<t<17.5 ℃), respectively. Under starvation, the regression equations were OR=13.723t^0.9738(n=650，R²=0.9974，4.5 ℃<t<17.5 ℃) and NR=0.1687t^1.0896(
n=650，R²=0.9977，4.5 ℃<t<17.5 ℃), respectively. The  optimal temperature range was 11.5 ℃-14.5 ℃. The juvenile S. fontinalus in starvation was heavily depended on fat and carbohydrates.

Key words: Salvelinus fontinalus, temperature, feeding, oxygen consumption rate , ammonia excretion rate, Eucalyptus and Corymbia, Bischofia javanica,  water consumption, water useefficiency.