NAD(P)H:quinone　oxidoreductase-1　(NQO1)　is　attractive　as　a　potential　cancer　biomarker　because　it　is　abnormally　expressed　in　many　solid　tumors　and　is　closely　related　to　a　variety　of　carcinogenic　processes.　Determining　and　evaluating　the　content/activity　of　NQO1　in　tumors　is　of　great　significance　for　early　cancer　diagnosis　and　therapeutic　effect　evaluation.　Enzyme-activated　imaging　probes　with　tailored　properties,　high　selectivity　and　sensitivity,　and　high　temporal　and　spatial　resolution　have　become　powerful　tools　for　detecting　and　monitoring　NQO1　activity.　In　this　review,　we　aim　to　offer　a　rigorous　but　succinct　overview　of　activatable　imaging　probes　by　reporting　the　significant　progress　made　in　accurately　detecting　and　imaging　NQO1　activity.　The　design　strategies,　mechanisms　and　applications　of　relevant　probes　are　rationally　analyzed　and　discussed.　We　also　emphasized　the　potential　challenges　and　prospects　of　NQO1-activated　imaging　probes　to　further　advance　the　development　of　diagnosis　and　therapeutic　methods　for　NQO1-related　cancers.　(C)　2020　Elsevier　B.V.　All　rights　reserved.