Two　inorganic-organic　hybrid　polyoxotantalates,　H-4[Na(H2O)(5)](2)[Co-II(en)(3)](2){[Co-III(en)](2)(Ta6O19)(2)}center　dot　22H(2)O　(1)　and　H2K2Na6　(H2O)(24){[Co-III(en)](2)(Ta6O19)(2)}33H(2)O　(2)　have　been　constructed　from　{[Co-III(en)(Ta6O19)](2)}(10-)　({Co2Ta12})　dimers.　Compound　1　has　a　three-dimensional　supramolecular　framework　with　a　pcu-type　topology.　Compound　2　possesses　a　three-dimensional　structure　composed　of　{Co2Ta12}　dimers　and　alkali　metal　ions　(Na+/K+)　via　coordination　bonds.　Polyoxotantalates　1　and　2　have　been　used　as　active　materials　for　ITO/1/Ag　and　ITO/2/Ag　RRAM　devices.　These　devices　exhibit　stable　non-volatile　storage　behavior　and　rewritable　resistive　switching　with　high　ON/OFF　ratios　of　1.43　x　10(3)　and　2.17　x　10(4)　for　1-based　and　2-based　RRAM　devices,　respectively,　and　stable　cyclic　performance　during　100-cycle　stability　tests.　This　discovery　opens　up　new　opportunities　for　the　development　of　electrical　bistability　materials.