Compounds　with　redox　activities　have　appealing　applications　in　catalytic,　electronic　and　magnetic　properties,　but　the　redox　inert　of　polyoxoniobates　(PONbs)　significantly　limits　their　applications　for　a　long　time.　In　this　work,　we　are　able　to　integrate　organophosphate　and　lanthanide　cluster　into　PONb　to　create　the　first　family　of　inorganic-organic　hybrid　organophosphate-Ln-PONb　composite　clusters.　These　novel　species　not　only　present　the　first　family　of　redox　active　PONbs　that　can　be　reduced　to　form　long-lived　“heteropoly　blues”　under　ambient　conditions,　but　also　a　new　photochromic　system.　More　importantly,　the　analyses　of　the　electronic　configurations　and　photochromic　properties　for　a　series　of　designed　proof-of-concept　PONbs　models　allow　us　to　discover　a　D-f-A　electron　transfer　mechanism,　that　is,　photoinduced　electron　is　transferred　from　a　photosensitive　organophosphate　electron　donor　(D)　to　the　NbV　electron　acceptor　(A)　through　the　unoccupied　4　f-orbitals　of　Ln　(f).　This　work　paves　the　way　for　developing　diverse　PONb-based　redox　materials　and　expanding　the　possibility　of　the　applications　of　PONbs　in　the　redox　chemistry.　©　2023　Wiley-VCH　GmbH.