Abstract: The study was undertaken to assess dietary CP and ME concentrations for optimum growth performance and carcass characteristics of Gaoyou ducklings. In a 3x3 factorial arrangement, three hundred and sixty zero-day-old Gaoyou ducklings were randomly assigned to experimental diets with 11.70, 11.90 and 12.12 MJ of ME kg-1 of diet; each contained 18.0, 19.0 and 20.0% CP, respectively, from 0-28 days of age. Each dietary treatment had 4 replicates. Body weight and feed consumptions were measured at every weekend, from 0-28 days of age and carcass characteristics were evaluated at 28 days of age. The result showed that ducklings on a diet with 11.70 and 11.90 MJ of ME kg-1 at 0-28 days of age exhibited greater BW gain than this diet with 12.12 MJ of ME kg-1 (p<0.01), though BW gain was not different among 11.70 and 11.90 MJ of ME kg-1 of diet. Mean BW gain of birds fed 18.0, 19.0 and 20.0% CP diets was significantly different (p<0.001). Feed intake was influenced by dietary ME levels (p<0.000) also. Feed intake of birds fed 18.0% CP diets was higher than those of birds on 19.0 and 20.0% CP diets (p<0.01). Feed conversion ratios of birds fed on 11.70 and 11.90 MJ of ME kg-1 of diet were better than those fed on 12.12 MJ of ME kg-1 (p<0.001). Feed conversion ratios of birds fed on 18.0% CP diets were better than those fed on 19.0 and 20.0% CP diets. In the study, there were significant interactions between dietary CP and ME on growth performance. There was a direct relationship between dietary ME levels and eviscerated carcass percentage (p<0.014), abdominal fat percentage (p<0.000) and breast weight (p<0.037). But the half-eviscerated carcass percentage, eviscerated carcass percentage, breast and leg meat percentage were not influenced by dietary CP concentration. Thus, diets with 11.70 MJ of ME kg-1 and 18.0% CP were used more efficiently from 0-28 days of age by Gaoyou ducklings.