In order to investigate Che nutritional value of seaweed as a dietary supplement, red sea bream Chrysophrys major were fed on the control diet without seaweed and on the diets supplemented with Wakame or Ascophyllum at a level of 5% or 10% to the control diet for 10 weeks. The growth and feed efficiency were best in the 5% Wakame diet group, followed by the 5% Ascophyl-lum, the 10% Wakame, the control, and the 10% Ascophyllum diet group. Besides this, the muscle lipid content was slightly higher in the 5% Wakame, the 5% Ascophyllum and the 10% Wakame diet groups, compared with the control and the 10% Ascophyllum diet groups.