Objective: Global consumption for chicken meat is steadily increasing. Carcass traits (e.g., slaughter weight [SW], eviscerated weight [EW]) are important economic traits for the meat production in chickens. Detection of genetic variants for these traits contributes to elucidating the genetic mechanism and accelerating genetic improvement. Methods: In this study, we performed a genome-wide association study on SW, EW, and thigh muscle weight (ThW), as well as the relative weight of these traits in 565 Sanhuang (SH) chickens. Additionally, genetic estimation has been conducted based on wholegenome variants for carcass traits. Finally, we compared the expression abundance of candidate genes to validate the function on carcass traits. Results: Except the percentage of SW (SP, 0.08), other traits were detected with moderate to high heritability (0.20-0.50). A high genetic correlation (0.72-0.93) was found among the carcass traits (SW, EW, and ThW). A total of 311 single-nucleotide polymorphisms and 73 candidate genes (e.g., IGF2BP1, BMP3, ACSL5) were identified significant association with carcass traits. IGF2BP1 was detected a causal role in EW and ThW, GIP, SNF8, and PHOSPHO1 were also located within the same genomic peak. CCND2 was related to SP and significantly expressed in commercial broilers and SH chickens. Lipid metabolism and immune function were simultaneously altered as a result of the selection for carcass traits. The genes ACSL5 and RASGEF1B were also significantly up-regulated in breast muscle in commercial broilers compared to SH chickens. Additionally, the transcriptomic profile of 73 candidate genes was constructed in multi-tissues, and a total of 17 genes (e.g., IGF2BP1, RASGEF1B, BMP3) were defined as differentially expressed genes between commercial broilers and SH chickens. Conclusion: In general, the findings in this study could facilitate the understandings of genetic mechanisms of carcass traits in chickens, and provide important variants and genes set for genomic breeding.