Abstract: The contents of growth hormone (GH) and triiodothyronine (T3) in serum,and protein and lipid in white muscles were measured for black seabreams (Sparus macrocephalus) in starvation for 2,5,10,15 and 30 days as treatments.At the same time the measurements were also made for the animals under normal condition as control.Testing for the difference between the treatment and control resulted in:1)the level of serum GH significantly increased after 15-day-starvation,and that of T3 decresed;2)the content of protein in white muscles decresed after 15-day-starvation,and the reduction of lipid occurred after 2 d and kept the low level to the end;3)the content of lipid in livers increased significantly after 10 d,and that of protein fluctuated irregularly.The increase of serum GH could ehance the translation of body materials into engery,and the reduction of T3 would reduce the metabolic rate,which could be viewed as physilological responses for the species to adapt the stress of starvation.