This study utilized largemouth bass （Micropterus salmoides） "Youlu No. 3" lines A and B， a salt-tolerant population， and the Sanshui population as breeding parents to construct 78 full-sib families. Genetic parameters and breeding values for growth-related traits in largemouth bass （Micropterus salmoides） were estimated using pedigree and phenotypic data. Heritability estimates were moderate for body weight （BW： 0.32 ±0.04）， body length （BL： 0.21 ±0.04）， average daily gain （ADG： 0.32 ±0.05）， and body shape index （BSI： 0.24 ±0.04）， whereas the condition factor （K） exhibited low heritability （0.14 ±0.03）. Genetic and phenotypic correlation analyses revealed a very high positive correlation between BW and ADG， with a genetic correlation coefficient of 0.99 ±0.001， indicating strong co-inheritance. High positive genetic and phenotypic correlations were also observed between BW and BL （r = 0.71-0.89） and between ADG and BL （r = 0.71-0.89）. The K value showed a strong positive genetic correlation with BSI （r = 0.93 ±0.04）， but a distinct negative phenotypic correlation with BL （r = -0.38 ±0.02）， suggesting potential trade-offs between body compactness and linear growth. The correlations between estimated breeding values （EBVs） and phenotypic values ranged from 0.597 to 0.740 across the five traits， indicating moderate agreement but substantial prediction error when relying solely on phenotype. Under a 10% selection intensity， the coincidence rates between top individuals selected based on single-trait EBVs versus phenotypic values were 46.2%， 49.0%， 43.4%， 47.4%， and 66.9% for BW， BL， ADG， K， and BSI， respectively. Notably， the average EBVs of individuals selected using the EBV-based method were significantly higher than those selected based on phenotypic values for all traits. The corresponding improvements in mean EBVs ranged from 23.1% （BSI） to 54.6% （K）， with gains of 40.8%， 34.1%， and 40.0% for BW， BL， and ADG， respectively. These results demonstrate that selection based on EBVs is substantially more effective than phenotypic selection in capturing additive genetic merit， thereby enhancing the accuracy and efficiency of genetic improvement programs for growth traits in largemouth bass.