The growth and development of theLongissimus Dorsimuscle are complex, playing an important role in the determination of pork quality. The study of theLongissimus Dorsimuscle at the mRNA level is particularly crucial for finding molecular approaches to improving meat quality in pig breeding. The current study utilized transcriptome technology to explore the regulatory mechanisms of muscle growth and intramuscular fat (IMF) deposition in theLongissimus Dorsimuscle at three core developmental stages (natal stage on day 1, growing stage on day 60, and finishing stage on day 210) in Ningxiang pigs. Our results revealed 441 differentially expressed genes (DEGs) in common for day 1 vs. day 60 and day 60 vs. day 210, and GO (Gene Ontology) analysis showed that candidate genesRIPOR2,MEGF10,KLHL40,PLEC,TBX3,FBP2,andHOMER1may be closely related to muscle growth and development, while KEGG (Kyoto Encyclopedia of Genes and Genomes) analysis showed that DEGs (UBC,SLC27A5,RXRG,PRKCQ,PRKAG2,PPARGC1A,PLIN5,PLIN4,IRS2,andCPT1B) involved the PPAR (Peroxisome Proliferator-Activated Receptor) signaling pathway and adipocytokine signaling pathway, which might play a pivotal role in the regulation of IMF deposition. PPI (Protein-Protein Interaction Networks) analysis found that theSTAT1gene was the top hub gene. Taken together, our results provide evidence for the molecular mechanisms of growth and development and IMF deposition inLongissimus Dorsimuscle to optimize carcass mass.