The cobia fed diets supplementing 8 and 16 ppm vitamin B1 had the better weight gain, and when cobia fed diet without vitamin B1 the weight gain was less than other treatment group(Initial average body weight, 22g.), but not any deficiency symptom had find in cobia during the experiment period. There were no significant difference in hepatosomatic index. The condition factor were high for cobia when fed diets containing higher vitamin B1 The test of interaction of vitamin B1 and carbohydrate was not significant different (Initial average body weight, 31g)