Abstract: We studied the effects of different carbohydrate (CBH) sources on the daily weight growth (DWG) and digestive enzymes activities of larval peanut worm (Sipunculus nudus) by feeding the larvae 7 isonitrogenous and isolipidic diets with glucose, sucrose, dextrin, tapioca starch, potato starch, corn starch or gelatinized corn starch as different CBH sources for 8 weeks. Results reveal that different CBH sources significantly affected the DWG of larval S.nudus (P < 0.05). Those fed with gelatinized corn starch and glucose had the highest and lowest DWG, respectively, significantly different from the other groups (P < 0.05).The DWG of those fed with 3 kinds of non-gelatinized starch were significantly higher than that of those fed with glucose, sucrose and dextrin (P < 0.05).The results of digestive enzymes analysis indicate that dietary CBH sources had significant effects on digestive enzymes activities (P < 0.05). Those fed with sucrose had the highest protease and amylase activities, significantly higher than the other CBH groups (P < 0.05). Those fed with glucose had the lowest lipase activity, significantly lower than the other CBH groups (P < 0.05). In conclusion, the effect of macromolecule carbohydrates (starch) on the growth of larval S.nudus is better than that of disaccharides (sucrose) and monosaccharides (glucose), and the growth effect of gelatinized corn starch is better than that of un-gelatinized corn starch.