Green　synthesis　of　metal-organic　frameworks　(MOFs)　in　water　with　alleviated　environmental　influence　and　reduced　cost　is　an　essential　step　to　transfer　laboratory　MOFs　research　to　industrial　application.　Switching　from　the　commonly　used　organic　solvents　to　pure　water　encounters　challenges　of　the　poor　solubility　of　organic　linkers,　slow　reaction　kinetics,　and　the　formation　of　polymorphic　products.　So　far,　a　universal　MOFs　synthetic　strategy　in　water　system　has　yet　to　be　developed.　This　study　reports　the　seed-aided　synthesis　of　eleven　MOFs　with　diverse　compositions　and　structures　while　pure　water　serving　as　solvent.　The　corresponding　reaction　temperature　and　time　of　using　this　new　strategy　were　reduced　compared　with　original　synthetic　approaches,　while　the　products　maintain　porous　structure　and　high　crystallinity.　The　success　of　this　strategy　relies　on　the　addition　of　parent　MOFs　as　seeds　which　could　promote　crystallization　process　by　skipping　the　time-consuming　induction　period　and　avoiding　the　formation　of　polymorphic　impurities.　©　2022　Institute　of　Process　Engineering,　Chinese　Academy　of　Sciences.