In　this　paper,　we　report　a　series　of　novel　mixed-metal-substituted　organic-inorganic　hybrid　polyoxometalates　(POMs)　H-3[(CH3)(4)N](14)[NaLn(PW11O39)(3)]center　dot　18H(2)O　(1-Ln,　Ln　=　Nd,　Sm,　Eu)　via　one-pot　solvothermal　synthesis　methods,　which　present　the　first　series　of　polyoxometalate　trimers　composed　of　both　alkali-metal-　and　lanthanide-substituted　keggin-type　POMs.　The　trimeric　heterometallic　polyoxoanions　in　1-Ln　show　an　interesting　linear　arrangement　and　can　be　further　packed　together　to　generate　a　packing　structure　with　cations　[(CH3)(4)N](+)　and　H3O+　filling　the　gaps　between　polyoxoanions.　Compounds　1-Ln　are　characterized　by　single-crystal　X-ray　diffraction　analysis,　TGA,　IR　and　PXRD.　Additionally,　the　luminescence　and　proton　conductive　properties　of　1-Ln　are　also　characterized.