Metallothioneins　(MTs)　are　a　class　of　non-enzyme　metal-binding　proteins　with　low　molecular　weight　and　rich　cysteine　residues.　MTs　have　many　biological　functions,　such　as　regulating　metal　homeostasis,　resisting　oxidative　stress,　and　screening　heavy　metals.　They　are　widely　used　in　food,　medicine,　environment,　cosmetics　and　other　fields.　There　have　been　a　lot　of　studies　on　the　gene　discovery,　expression　regulation,　structural　characterization,　functional　identification　and　application　range　expansion　of　MTs.　However,　MTs　are　far　from　being　fully　understood　due　to　the　diversity　and　complexity　of　their　species,　structure　and　function.　Based　on　the　comprehensive　analysis　of　the　literature　related　to　MTs　in　the　world,　the　current　research　status　and　dynamic　hot　spots　in　the　field　of　MTs　were　reviewed,　which　mainly　included　the　following　five　aspects:　the　species　and　structures,　gene　expression　and　its　regulation,　zinc　and　copper　homeostasis,　the　role　of　MTs　in　the　biomedical　field,　and　the　application　of　MTs　in　the　remediation　of　heavy　metal　contamination.　After　sorting　out　the　problems　and　challenges　in　the　field,　it　was　found　that　the　future　research　of　MTs　tends　to:　the　development　of　microbial-derived　MTs,　efficient　expression　and　preparation　of　MTs,　establishment　of　new　high-resolution　characterization　methods　for　MTs,　exploration　of　the　correlation　between　metal　bio-dynamics　and　induced　expression,　and　application　expansion　of　MTs.　©　2025　China　Biotechnology　Press.　All　rights　reserved.