摘要Affinity selection mass spectrometry(AS-MS)has emerged as a powerful label-free technique for identifying and characterizing ligand-target interactions.This review explores the diverse applications of AS-MS in drug discovery,including its role in selective screening,binding site characterization,and quantitative affinity determination.We discuss the use of AS-MS for determining equilibrium dissoci-ation constants(KD)and competitive binding parameters(affinity competition experiment 50％(ACE50)),highlighting its ability to rank ligand affinities efficiently.The review also examines AS-MS applications in fragment-based drug discovery(FBDD),screening for molecular glues,and investigating interactions with membrane proteins.Moreover,we address key technical challenges,including competitive binding effects,protein stability,and ligand dissociation kinetics,along with recent advancements in automa-tion and artificial intelligence(AI)integration.Rather than providing a comprehensive literature review,this work aims to broaden the applicability of AS-MS assays and encourage researchers to explore its use in underutilized contexts.By providing rapid and high-sensitivity affinity measurements,AS-MS con-tinues to expand its role in drug discovery and structural biology,complementing conventional bio-physical techniques.