Abstract: This study aims to investigate the distribution characteristics and bioaccumulation patterns of persistent organic pollutants (POPs) in different tissues of mussels from Huaniao Island along the coastal East China Sea. The concentrations of hexachlorocyclohexanes (HCHs), dichlorodiphenyltrichloroethanes (DDTs), chlordanes (CHLs), and polychlorinated biphenyls (PCBs) in various tissues (mantle, muscle, gonad, digestive gland, gill, and byssus) were determined using gas chromatography-tandem mass spectrometry (GC-MS/MS). A comparative analysis was conducted based on data normalized to dry weight and lipid weight. Among the target pollutants in mussels, the concentration of ΣDDTs was the highest (865 μg/kg lipid weight), followed by ΣHCHs (24.3 μg/kg lipid weight), ΣPCBs (13.8 μg/kg lipid weight), and ΣCHLs (13.7 μg/kg lipid weight). On a dry weight basis, concentrations increased from external to internal tissues. Conversely, an opposite trend was observed on a lipid weight basis. Congener-specific ratios e.g., γ-HCH/β-HCH, DDT/(DDD+DDE) indicated that highly toxic substances mainly remained in external tissues. Degradation products or less toxic congeners tended to migrate towards the internal tissues. The fitting analysis between log BCF and log Kow showed that the byssus exhibited the strongest bioaccumulation capacity (log BCF_max=6.65), followed by muscle (6.41), while the gonad showed the weakest (6.05). Significant differences were observed in the accumulation patterns of POPs among different mussel tissues. Lipid content was an important factor influencing their distribution. Highly toxic compounds tended to be enriched in the external tissues, while internal tissues were dominated by less toxic metabolites. This study reveals the mechanisms underlying differential POP accumulation across mussel tissues. It provides a scientific basis for accurately assessing the role of organisms in pollutant transport and the associated marine ecological risks.