Of the thousands of known chemical reactions, a handful of reactions, called "click" reactions, stand out with features such as good chemoselectivity, good solvent compatibilities, modularity, minimum synthetic demands, bioorthogonality and high yields. Among them, the Cu(i)-catalyzed 1,3-dipolar cycloaddition reaction between azides and terminal alkynes has emerged as a powerful tool in chemical biology and proteomics. This perspective surveys the significant contributions of click chemistry in catalomics (a sub-area in chemical proteomics), with special emphasis on activity-based protein profiling (ABPP), posttranslational modifications (PTMs) and enzyme inhibitor developments.