In this study, we collected an in-depth quantitative proteomic dataset of poorly and non-poorly differentiated gastric adenocarcinoma from both tissue and interstitial fluid levels and presented a comprehensive analysis from several aspects. The ISF proteome has higher abundances in proteins of blood microparticle, protein-lipid complex, immunoglobulin complex, and high-density lipoprotein particle etc. Correlation analysis of protein abundance changes between tissues and the matched ISFs uncovered consistent and inconsistent biological events.