An 8-week feeding trial was conducted to investigate the effects of dietary glycyrrhetinic acid(GA)levels on growth,lipid deposition and antioxidant capacity of juvenile blunt snout bream,Megalobrama amblycephala[average initial weight:(15.63±0.04)g].Triplicate groups of fish were fed three times daily with five isonitrogenous and isoenergetic diets containing 0(control group),0.15,0.30,0.45 and 0.60 g/kg GA,respectively.The results indicated that dietary GA levels had little effects on weight gain,specific growth rate,feed conversion ratio,whole body and muscle lipid contents as well as serum triglyceride,free fatty acid and high-density lipoprotein cholesterol levels of blunt snout bream(P>0.05).However,the viscerosomatic index,hepatosomatic index,intraperitoneal fat ratio,liver lipid content and lipoprotein lipase,hepatic lipase and total lipase activities of fish fed GA supplemented diets were all significantly lower than those of the control group(P<0.05).Serum cholesterol concentration of fish fed 0.30-0.60 g/kg GA was significantly lower than that of the control group(P<0.05).Lipase activity increased significantly in the groups fed on diets adding 0.30-0.60 g/kg GA(P<0.05).In addition,liver superoxide dismutase and reduced glutathione activities of fish fed GA supplemented diets were both significantly higher than that of the control group,whereas the opposite was true for malondialdehyde content(P<0.05).In conclusion,dietary inclusion of 0.30-0.45 g/kg GA could reduce the lipid deposition.The mechanism may be that GA could strengthen lipid degradation and enhance lipid metabolism enzymes activities.Moreover,the GA supplemented diets can promote antioxidant capacity in blunt snout bream.