We analyzed the associations between the polymorphisms of the PRL (prolactin) gene and the growth traits and flesh components of the grass carp, . Six variable sites with mutation rates exceeding 30% were detected in 10 individuals by sequencing the full length of the gene. These included five single-nucleotide polymorphic loci and one insert mutation (-/CACTCACTA), designated > -/+, respectively. The polymorphisms at the variable sites were examined in 192 juvenile using allele-specific PCR and genotyping. The associations between the polymorphisms at these loci and the growth traits and flesh components of the fish were analyzed with general linear models. The polymorphisms at three loci () and one locus () were significantly associated with growth traits and the flesh protein content ( < 0.05), respectively. Multiple comparisons of the traits were made with the genotypes at each locus. The standard length and bodyweight of individuals with the mutant genotypes (-+ and ++) at ->+ were significantly higher than those of individuals with the wild-type genotype (- -) ( < 0.05). In contrast, the standard length and bodyweight of individuals with the mutant genotypes at (TG and GG) were significantly lower than those of individuals with the wild-type genotypes at < 0.05). For the, Individuals with the mutant genotype CC at had significantly higher flesh protein content than individuals with the other genotypes (GG and GC) ( < 0.05). Similar results were found in multiple comparisons for the traits of two loci groups. The standard length and bodyweight of individuals that contained mutant genotypes (-+ and ++) at ->+ were generally higher than those of individuals with the wild-type genotype (- -). The fat and protein contents of individuals that contained the mutant genotype CC at were generally higher than those of individuals with the other genotypes (GG or GC), and the protein contents were significantly different ( < 0.05). Overall, there were significant associations between the polymorphisms of the . Therefore, the different variable sites in the gene might have utility as markers for practical breeding programs for growth traits and flesh components in .