Abstract: To investigate the changes of GH, IGF-I, RNA/DNA ratio and glycogen content of brown flounder (Paralichthys olivaceus) to thermal manipulation, we cultured the juveniles at 8.5 ℃(T_8.5), 13.0 ℃(T_13.0), 17.5 ℃(T_17.5), 22.0 ℃ (T_22.0) and 26.5 ℃ (T_26.5) for 10 d, and then adjusted to 22.0 ℃ for 30 d. The plasma IGF-I concentration of T_17.5 was lower than that of T_22.0 during stress period, but no significant difference was found in plasma GH and IGF-I concentration at different temperatures during stress and restoration periods. RNA/DNA ratios were significantly different in liver during 20~40 d but not significantly different in muscle during the whole experimental period. The glycogen contents in liver of T_8.5, T_13.0 and T_26.5 were significantly lower than that of T_17.5. At the end of the experiment, the glycogen contents in liver of T_8.5, T_13.0, T_17.5 and T_26.5 were slightly higher than that of T_22.0. The glycogen contents in muscle of T_26.5 and T_13.0 were the highest at the end of stress period and on 20^th day, repectively. The slow growth caused by 10-day culture at different temperatures could be completely compensated in 30 d after the temperature was adjusted to 22.0 ℃. No significant correlation was detected among plasma GH, IGF-I concentration, RNA/DNA ratio and growth rate.