Carbohydrates are widely included in aquafeed as the major non-protein energy source owing to theirwide availability and low cost. This study evaluated the effects of the quantity of dietary carbohydrates (25.61%,34.55%, 45.31%, 55.82%, 66.09%) on growth performance, feed utilization, body composition, and the energybudget of juvenile (Selenka) sea cucumbers. Sea cucumbers were given feed with the differentpercentages of carbohydrates for 60 days, with 3-replicates per treatment and 40 sea cucumbers per replicate[ ±SE: (1.67±0.06) g, body weight]. During the experiment, the specific growth rate and feed conversion efficiencyinitially increased then decreased with higher levels of dietary carbohydrates. Based on second-orderpolynomial regression models of these variables, optimal carbohydrate levels for the sea cucumber were estimatedto be 50.15%–53.95%. The protein efficiency ratios and energy consumed were significantly higher in diets with45.31%–55.09% carbohydrates than in those with 25.61%–34.55%, demonstrating that carbohydrates providedenergy for protein sparing. Dietary carbohydrate intake had significant effects on sea cucumber feed intake, fecesproduction, and apparent digestibility coefficient. Optimal carbohydrate intake enhanced the efficiency of nutrientutilization. Whole body, body wall, and intestinal crude lipid content all increased with higher levels of dietarycarbohydrates, where excess carbohydrates resulted in tissue lipid deposition. In diets with 66.09% carbohydrates,the percentage of energy intake used for growth significantly decreased, while energy accounted for by feces, excretion,and respiration increased, indicating that excess dietary carbohydrates reduced energy utilization efficiency.In conclusion, optimal levels of dietary carbohydrate intake promoted growth and feed utilization in theseacucumber, while lipid deposition and energy metabolism variability resulted from excess dietary carbohydrates.