Abstract:This experiment was conducted to study growth performance of juvenile zander[initial average weight(7.75±1.17) g]fed five formulated diets with different lipid(energy) to protein ratios.The results showed:The specific growth ratio[SGR (2.86±0.17)%/d],feed coefficient ratio(FCR 1.57±0.12),protein deposit ratio(PDR 98.44%±2.38%),energy retention ratio(ERR 30.88%±3.83%) performed the best in group 4 after being fed the different diets;Using the secondorder polynomial regression analysis, the optimum protein,the optimum lipid,the optimum gross energy(GE),the optimum lipid to protein ratio(L/P) and the optimum energy to protein ratio(E/P) in diets for juvenile zander (Lucioperca lucioperca) were estimated based on SGR, PDR and ERR of the juveniles. When SGR was the highest, the optimum protein, the optimum lipid, GE, L/P and E/P were estimated to be 39.80%,8.79%,18.53 MJ/kg,0.22,46.56 kJ/g;When PDR was the highest, the optimum protein, the optimum lipid,GE,L/P and E/P were estimated to be 38.76%,9.18%,18.65 MJ/kg, 0.24, 48.12 kJ/g;When ERR was the highest, the optimum protein, the optimum lipid, GE, L/P and E/P were estimated to be 38.55%,9.45%,18.72 MJ/kg, 0.25, 48.56 kJ/g;The requirement for protein used for energy is decreased when dietary lipid level increases.It was suggested that dietary lipid had significant proteinsparing effect on this fish. But zander (Lucioperca lucioperca) utilizes the lipid definitely;When E/P was as high as 58.79 kJ/g or as low as 42.54 kJ/g,WGR,PDR and ERR were significantly lower,FCE was significantly higher(P<0.05) than other E/P levels,indicating that diets with too high E/P level or low E/P level would inhibit the growth and feed utilization of juvenile zander.