---

The present study investigateeffect of different dietary macronutrient composition on fatty acids profile, body fat and pancreatic lipase enzyme activity in Siberian sturgeon. A group of 180 Siberian sturgeons juvenile (initial weight, 30 ± 5 g) were used in this experiment and fed on four isoenergetic diets. Diets were named LP-St (low protein and high carbohydrate: lipid ratio), HP-St (high protein and high carbohydrate: lipid ratio), LP-L (low protein and low carbohydrate: lipid ratio) and HP-L (high protein and low carbohydrate: lipid ratio). Fish were fed apparent satiety for 10 weeks. The samples were obtained from body carcass and juveniles intestine. In this study, the same level of fish oil and sunflower oil were used as a source of diet lipid content. The HUFAs content in HP-St and LP-L diets were showed highest and lowest value, respectively. The results showed the body fatty acidsprofiles was significantly affected by fatty acids composition in diets (P < 0.5). Diets with high protein and high carbohydrates concentrated SFA and MUFA in fish carcass. Moreover, the PUFA content increased in sturgeon fed with high lipid diet. However,the results of this study showed the body lipid content wasaffected by total lipid content of diet and lipase activity decreased in Siberian sturgeon intestine fed on LP-L diet with lowest HUFA.