Jiangsu province is rich in intertidal marine resources,especially gastropod and bivalve shellfish.In this study,we performed shotgun proteomic analysis on shellfish from Lüsi,Jiangsu to identify protein content.In total,265 proteins were identified in nine species of shellfish using nano LC-MS/MS.The highest number of proteins were identified in the gastropod Hemifusus tuba (HF) (105 proteins),whereas the bivalve Scapharca subcrenata (SSC) produced the fewest (39 proteins).The most abundant proteins are constituents of cytoskeleton,including actin,tubulin,tropomyosin,myosin heavy chain,as well as histone proteins.Additional proteins were also identified,including ribosomal proteins,enzymes such as arginine kinase and ATP synthase,and housekeeping proteins such as elongation factor and heat shock protein.Proteins were classified based on cellular components and molecular function using the principal component analysis (PCA).Results of PCA analysis revealed that Sinonovacula constrzcta (SC),Bullacta exarata (BE) and Hemifusus tuba (HF) showed similar protein profiles,whileSolen strictus (SS),Meretrix meretrix (MM),Ruditapes philippinarum (RP),and Mactra veneriformis (MV) also showed similar protein profiles.Hierarchical clustering results of heat map studies showed that RP and Mactra antiquate (MA) were classified into one group.SC,BE,HF,MM,SSC,and MV were classified into another group.SS showed the furthest distance from this group.We established a method for analyzing and characterizing the protein composition characteristics of predominant shellfish species in Jiangsu providence's intertidal zone area,which provides basic data for the development of shellfish resources.