The　blockchain　technology　has　been　changing　our　daily　lives　since　Bitcoin-i.e.,　the　first　decentralized　cryptocurrency-was　invented　and　released　as　open-source　software　by　an　unidentified　person　or　a　group　called　Satoshi　Nakamoto　in　2009.　Of　many　applications　which　can　be　implemented　based　on　the　blockchain,　storage　is　an　important　one,　a　notable　example　of　which　is　the　InterPlanetary　File　System　(IPFS).　IPFS　is　a　distributed　web　based　on　a　peer-To-peer　hypermedia　protocol　to　make　the　web　faster,　safer,　and　more　open　and　focuses　on　public　accessible　files.　To　provide　a　solution　for　private　file　storage　in　the　blockchain　way,　in　this　paper　we　propose　a　Merkle-Tree-based　File　System　(MTFS).　In　MTFS,　the　blockchain　is　more　than　a　trust　machine;　it　is　an　abstract　of　a　cluster　system.　Distributed　random　nodes　form　a　tree　network　cluster　without　a　central　controller　to　provide　a　secure　private　storage　service　and　faster　message　propagation.　Advance　proxy　re-encryption　algorithm　is　applied　to　guarantee　secure　file　exchanges　under　permission.　Merkle　tree　will　make　sure　that　the　files　are　distributed　among　the　service　nodes　in　a　balanced　way.　The　proposed　MTFS　can　be　used　not　only　for　personal　file　storage　and　exchange　but　also　for　industry　requiring　mutual　trust　in　file　uploading　and　downloading　in　making　contracts　like　insurances.　©　2019　IEEE.