Abstract: The Diurnal rhythm of oxygen consumption and effects of body weight and temperature on oxygen consumption rate of Sparus macrocephalus were examined under a flowing-water apparatus. The results revealed that the oxygen consumption rate of S.macrocephalus exhibits an increase with the rise of water temperature but a decrease with the increment of body weight. The rate of oxygen consumption varied with the alternation of day and night. The highest oxygen consumption rate was 3.160.26 g(gmin)-1 at 11:00pm, and the lowest 0.740.59 g(gmin)-1 at 7:00am. The mean oxygen consumption rate was 1.980.84 g(gmin)-1 at day and 1.960.63 g(gmin)-1 at night. The results showed that the change of metabolism level of S.macrocephalus is not significantly between day and night (n=10, t=0.034＜t0.05)。