A feeding trial was conducted to evaluate the effects of dietary tert-butylhydroquinone (TBHQ) on growth performance, blood biochemical parameter, non-specific immunity and intestinal tissue structure of turbot (Scophthalmus maximus). Four isonitrogenous and isoenergetic diets were formulated to contain graded levels (0, 150, 450 and 750 mg/kg) of TBHQ. Fish[initial average weight (8.31±0.04) g] were randomly allocated to 24 tanks, and each tank was stocked with 30 fish. Fish were fed twice daily to apparent satiation for 12 weeks. The results indicated that fish fed the diets containing 450 and 750 mg/kg TBHQ had significantly lower weight gain ratio and specific growth rate than that of fish fed the basal diet (the control group). Fish fed the diet containing 450 mg/kg TBHQ had significantly higher activity of serum alkaline phosphatase than that of fish fed the diet containing 150 mg/kg TBHQ. Fish fed the diet containing 150 mg/kg TBHQ had significantly lower albumin and high density lipoprotein content than that of fish fed the basal diet and the diet containing 450 mg/kg TBHQ; fish fed the diet containing 450 mg/kg TBHQ had significantly higher serum creatinine content than that of fish fed the basal diet; fish fed the diet containing 150 mg/kg TBHQ had significantly lower serum total protein content than that of fish fed the basal diet. Fish fed the diets containing 450 and 750 mg/kg TBHQ had significantly higher activity of serum CAT, lysozyme activity, and fish fed the diet containing 750 mg/kg TBHQ had significantly higher respiratory burst activity of renal phagocytes. Fish fed the diet containing 750 mg/kg TBHQ had significantly lower serum SOD activity. Fish fed the diets containing 450 and 750 mg/kg TBHQ had significantly lower ratio of intestinal villus length to bowel diameter than that of fish fed the basal diet, and fish fed diet containing 750 mg/kg TBHQ had significantly lower ratio of microvillus length to bowel diameter than that of fish fed the basal diet. In conclusion, the results of the present study indicated that 150 mg/kgTBHQ in diets of juvenile turbot had no significant effects on weight gain, physiological or biochemical indexes, while fish fed diet with more TBHQ (>450mg/kg) had negative effects on the growth and physiological status.