It is well known that niacin plays an important role in metabolism with regards to protein, lipid and carbohydrates. Fish fed with a niacin deficient diet may show poor growth, lower feed conversion, skin or fin damage, and anemia. So far, reports regarding the effects of niacin on growth, flesh quality and antioxidant function in hybrid sturgeon () are relatively few in number. Therefore, this study was undertaken to evaluate the effects of dietary niacin on growth performance, muscle composition, muscle quality and antioxidant function of juvenile hybrid sturgeon. Four test diets were prepared by adding 0 mg/kg, 30 mg/kg, 120 mg/kg and 1200 mg/kg of niacin, respectively. The juvenile hybrid sturgeon, which had an initial body weight of (54.41±0.79) g, were fed for 12 weeks. The experiment was divided into four treatments, each treatment with three replicates and 15 fish in each replicate. The results showed that weight gain rate was significantly affected by the dietary niacin level (<0.05). The weight gain rate of the 0 mg/kg niacin group was significantly lower than that of the 30 mg/kg, 120 mg/kg and 1200 mg/kg niacin groups (>0.05), and no significant differences were observed among the other niacin groups. The survival rate, feed conversion rate, and viscerosomatic index were not affected by the dietary niacin level (>0.05). The condition factor of the 120 mg/kg niacin group was significantly lower than that of the 0 mg/kg, 30 mg/kg and 1200 mg/kg niacin groups (>0.05), and there was no significant difference between the 0 mg/kg, 30 mg/kg and 1200 mg/kg niacin groups (>0.05). The hepatosomatic index of the 120 mg/kg niacin group was significantly lower than that of the 0 mg/kg and 1200 mg/kg niacin groups (<0.05), and no significant differences were observed between the 30 mg/kg and 120 mg/kg niacin groups (>0.05). The muscle hardness and springiness increased first and then decreased with increasing dietary niacin. The muscle hardness and springiness of the 1200 mg/kg niacin group was significantly lower than that of other niacin groups (<0.05). The muscle chewiness, resilience and gumminess of the 30 mg/kg niacin group was the highest among all groups, and was significant higher than that of the 0 mg/kg, 120 mg/kg and 1200 mg/kg niacin groups (<0.05). The muscle cohesiveness of the 30 mg/kg niacin group was significant higher than that of the 0 mg/kg, 120 mg/kg and 1200 mg/kg niacin groups (<0.05), and there was no significant difference between the 0 mg/kg, 120 mg/kg and 1200 mg/kg groups (>0.05). The muscle composition of crude protein, crude lipid, ash and moisture content were not affected by the dietary niacin level (>0.05). The muscle T-SOD activity of the 30 mg/kg niacin group was significant higher than that of the 0 mg/kg and 120 mg/kg niacin groups (<0.05), but there was no significant difference between the 1200 mg/kg and 120 mg/kg niacin groups (>0.05). Similarly, the muscle T-AOC activity of the 30 mg/kg niacin group was significant higher than that of the 0 mg/kg, 120 mg/kg and 1200 mg/kg niacin groups (<0.05), and there was no significant difference in T-AOC activity between the 0 mg/kg, 120 mg/kg and 1200 mg/kg niacin groups (>0.05). The key finding here is that dietary niacin (≥ 30 mg/kg) can improve the growth, muscle quality and antioxidant capacity of hybrid sturgeon.