Update publication information. Laying period is one of the important factors influencing fat metabolism and meat quality in hens. To evaluate the protein expression profiles during laying lasting, a total of 45 female Beijing-You chicken (BYC) hens, fed on the same diet, were collected at the slaughter age of 150, 300, or 450 days (D150, D300, and D450) from sexual maturation stage to culling stage (15 birds per age). A tandem mass tag (TMT)-based quantitative proteomic strategy was applied for proteomic characterization in thigh muscle of BYC. A total of 4,465 proteins in thigh muscle and 341 of them were differentially expressed (fold change ≥ 1.5 or ≤ 0.67 and p < 0.05). There were 145 up- and 36 down-regulated proteins in D150 vs. D300 group, 181 up- and 90 down-regulated in D150 vs. D450 group, and 10 up- and 56 down-regulated in D300 vs. D450 group. The proteomic profiles of BYC at D300 were very similar to those at D450 and highly different from those at D150, suggesting that D150 might be an important chronological age for BYC. According to the p-values, 96 differentiallly expressed proteins (DEPs) were screened out from the top 10 terms and pathways of Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. These DEPs presented 11 significantly enriched (P < 0.05) pathways, including taurine and hypotaurine metabolism, ECM-receptor interaction, spliceosome, cardiac muscle contraction, p53 signaling pathway, glycosphingolipid biosynthesis, and the pathways for cell differentiation (oocyte meiosis and cell cycle). In addition, there existed several representative DEPs (SERPINA3, SERPINA4, COL3A1, COL1A1, COL1A2, COL4A1, apoA-Ⅰ, apoA-IV, VTG1, VTG2, YWHAZ, YWHAQ and YWHAH) involved in the regulation of extracellular structure organization, lipid transportation, cellular metabolism and development, respectively. Furthermore, a total of 8 DEPs were quantified using parallel reaction monitoring (PRM) to validate the results from TMT analysis. Overall, the present work could strengthen our view of the temporal expression profile during development and identify novel biomarkers for genetic breeding of chickens.