A　Sb-embedded　polyoxoniobate　has　been　originally　synthesized　under　hydrothermal　conditions.　Particularly,　the　peanut-like　[Sb2Nb24O72](18-)　cluster　cage　in　1　with　C-2h　symmetry　is　composed　of　two　9-nuclear　{SbNb9O33}　motifs　and　one　{Nb6O24}　crown-shaped　ring.　The　compound　1　present　the　novel　structure　of　Sb-substituted　sandwich-type　polyoxoniobate　with　antimoniobate　cluster　cage.　Decomposition　catalytic　studies　indicate　that　compound　1　exhibits　good　hydrolytic　activity　and　stability　on　the　degradation　of　nerve　agent　simulant　dimethylphosphonate　(DMMP).