Abstract: The metabolic rate changes of juvenile turbots(Scophamus maximus) were determined when the salinity changed abruptly from 34 to lower levels(28, 23, 18, 12, 8 salinity) and to a higher level (40 salinity). The results show that all of the oxygen consumption rates and ammonia excretion rates of juvenile turbots of the 6 groups have a slowly increasing trend, and the bigger extent salinity changed, the more distinct trend appeared. After salinity changing, it was about at the 24 h of the experiment that the peak level of oxygen consumption rate was found. However, the highest ammonia excretion rate was seen only at 9~15 h after the experiment began. And at the end of the experiment, oxygen consumption and ammonia excretion rates of juvenile turbot came back to the former level before salinity changing, and no significant differences were observed in all groups (P > 0.05).