Abstract:is an important species in the Chinese economic aquiculture industry. Therefore, it is imperative for us to study the growth regulatory mechanisms of to help improve the growth trait and cultivate new varieties with higher growth rates. To learn more about the molecular mechanisms behind the growth of , the muscle transcriptomes of fish with different weights were sequenced. Despite being cultivated under the same conditions, the from full-sib families showed differences in the growth traits. After three months, 5 overweight and 5 underweight individuals were selected. The weight of the overweight group was 4 times heavier than the that of the underweight group. Muscle transcriptome sequencing was conducted to determine the differences in the gene expression patterns between the overweight and underweight groups. In all, 73353 unigenes were obtained with an average size of 703 bp. Then, 39005 unigenes were annotated by searching against NR, COG, Swissprot, and KEGG. After RPKM comparison, 8942 differentially expressed genes (DEGs) were confirmed, which were mainly found in the underweight group. , and Troponin have a higher gene expression in the underweight group. According to the KEGG pathway, many different expression genes are enriched in pathways concerning protein processing in the endoplasmic reticulum, ubiquitin-mediated proteolysis, and RNA transport. The expression trends of genes relating to protein synthesis and muscle fiber synthesis appear to be consistent. In general, the study showed that with different growing characteristics have different transcriptome expression patterns. The underweight fish are smaller in size and present higher gene expression activities. This data provides rich genetic resources for studies on the growth regulation of .