Abstract: We measured the total anti-oxidation capability (T-AOC), superoxide dismutase (SOD) activities, malondialdehyde (MDA) levels, Na+/K+-ATPase activity and biochemical composition in the branchial filament, liver and muscle of Trachinotus ovatus after starvation. The results show that the T-AOC increased in the branchial filament and muscle after 7-day starvation, whereas significantly decreased in the liver (P0.01). The SOD activities increased significantly in the branchial filament and muscle (P0.01), but had no significant difference in the liver (P0.05). The MDA levels in the branchial filament, liver and muscle increased after starvation, especially very significantly in the branchial filament (P0.01), significantly in the liver (P0.05), but not significantly in the muscle (P0.05). The Na+/K+-ATPase activity increased significantly in the branchial filament (P0.01) and in the muscle (P0.05) but decreased significantly in the liver (P0.01) after 8-day starvation. The moisture contentin the whole body of juveniles T.ovatus increased while the crude fat, crude protein and energy values decreased greatly during starvation; and the relative loss rate of crude fat was bigger than that of crude protein, indicating that juvenile T.ovatus utilizes fat as energy source in early starvation, and with the extension of starvation, the protein will be consumed.