This study was done is three phase ,to required suitable level of protein and energy and optimum carbohydrate to lipid ratio (B.xanthopterus) fingerling . Phase one: Determine of dietary protein and energy l eve in tanks (300 liters) treatment with triplicate e in different level of protein (25 ,30 ,35 percentage) and three level of energy (250 ,300 ,350 kcal/gr) the result showed that the best (GSR and WG) belongs to diet with protein % 35 and 300 kcal/gr. this experiment showed with increased of protein , SGR and WG increased and the one special level of protein with increased of energy level ,first SGR and WG increased (the most of SGR belonged 300 kcal/gr) ,and SGR decreased. Phase 2 : Determine optimum lipid to carbohydrate ratio in tanks (300 liters) In this phase with suitable level of protein and energy( protein %35 and 300kcal/gr) determined 5 ratio of carbohydrate and lipid (0.8, 2.8, 4.86, 8.8 ) in this phase best diet determined with 4/8 ratio , and 6/8 , 2/8 ratios were after that carbohydrate and lipid ratio. Phase 3: Determine optimum lipid to carbohydrate ratio in pond: In this phase, the result of thirty phase were like second phase. we determined that the best SGR and WG and WG % belonged to 4/8 carbohydrate and lipid ratio and 6/8 2/8 ratio were after 4/8 carbohydrate and lipid rate
