This study evaluated the effects of substituting fishmeal with cottonseed protein concentrate (CPC) on growth,flesh quality and gossypol deposition of largemouth bass, Micropterus salmoides. A basal diet was formulated to contain 700 g/kg fishmeal, and then CPC was used to replace 0% (FM), 15% (C15), 30% (C30), 45% (C45), 70%(C70) of dietary fishmeal. The five diets were fed to largemouth bass with initial body weight of 95.3 g for 12 weeks. The results indicated that 45% of fishmeal could be successfully replaced by CPC without significant impacts on weight gain (WG) and feed conversion ratio (FCR) (P > 0.05), while WG was decreased by 11.7% andFCR was increased by 0.22 when 70% fishmeal was replaced by CPC. The retention efficiencies of crude protein and essential amino acids were affected linearly or quadratically by dietary CPC levels (P < 0.05). Compared to

FM group, the flesh composition (crude lipid, amino acids contents) and texture (chewiness, cohesiveness and shear force) were decreased significantly in C70 group, while higher polyunsaturated fatty acids level was found in C15-C70 groups (P < 0.05). In water-holding capacity, higher flesh drop loss at 12th h and lower centrifugal loss were observed in C15-C70 groups than those in FM group (P < 0.05). All CPC groups showed significant lower serum cholesterol content than the FM group (P < 0.05). The serum glucose, triglyceride and total protein contents in C70 group were significantly lower than those in FM group (P < 0.05). In addition, no significant differences were observed in flesh free gossypol contents among the groups of FM, C45 and C70 (P > 0.05). Conclusively, up to 45% fishmeal could be successfully replaced by CPC without compromising the growth, flesh composition, texture, flavor characteristics and antioxidant capacity, while 70% fishmeal replacement by CPC produced negative effects on the growth performance and flesh quality of largemouth bass.