Carbon　quantum　dots　(CQDs),　a　new　type　of　fluorescence　carbon　nanomaterials　with　particle　size　varied　from　2　to　10　nm,　have　attracted　much　attention　due　to　their　strong　multi-color　luminescence　properties,　unprecedented　biocompatibility,　excellent　aqueous　dispersibility　and　easy　preparation　from　a　wide　range　of　carbon　materials.　These　multiple　attributes　help　CQDs　possess　a　broad　range　of　prospective　applications　in　numerous　fields,　especially　for　bio-imaging,　drug　delivery,　chemical　probe　and　photon　therapy　because　of　their　advantages　of　low　cytotoxicity　and　good　biocompatibility.　Therefore,　it　is　necessary　to　recap　the　synthesis　and　application　of　CQDs-based　materials　in　the　field　of　biomedicine.　The　methods　for　the　synthesis　of　CQDs　are　introduced　firstly,　and　then　different　performance　of　CQDs　related　to　their　applications　are　demonstrated　and　discussed,　including　the　function　tailoring　of　CQDs.　Finally,　future　opportunities　and　challenges　of　CQDs-based　materials　in　this　burgeoning　field　are　proposed　from　the　perspective　of　the　rational　design　of　systematic　CQDs-based　materials　toward　the　biomedicine　field.　©　2021　Elsevier　Ltd