The effects of citric acid supplementation in diets were evaluated on the growth, nutrient utilization, and nitrogen (N) and phosphorus (P) secretion of largemouth bass (Micropterus salmoides). Three diets were prepared with the addition of monocalcium phosphate (MCP) at 5, 10 (low-P diets), and 15 g/kg (positive control) (P5, P10, P15), then 10 g/kg of citric acid was added into the two low-P diets of P5 and P10. The five diets were fed to juvenile fish[initial body weight (16.0 ±0.16) g] for 60 days. The results showed that the weight gain (WG), whole body P, crude protein retention, P digestibility, vertebral P and plasma P significantly increased, and N excretion, whole body crude lipid decreased with the increasing MCP level (P<0.05); P15 group showed the best performance among all the groups. The addition of citric acid in P5 diet significantly increased WG (+5.6%) and serum P level, and reduced FCR (-0.05) and N excretion (P<0.05), which reached the similar levels to the P10 group (P>0.05). The addition of citric acid in P10 diet numerically improved the growth performance with similar levels to the P15 group (P>0.05). The supplementation of citric acid in both P5 and P10 diets significantly promoted P digestibility and reduced P excretion (P<0.05). In summary, the addition in 10 g/kg citric acid in low-P diets can improve the growth and the utilization of P and diet in largemouth bass.