Three　polyoxovanadium　clusters,　[{Ni(phen)2}2V4O12]　·H2O　I,　[N(CH2CH2)3NH]　Na(H2O)6　{K4(H2O)4[V10　O28]}(H2O)4　II　and　[(CH3)4N]6　[V15O36Cl]　III,　have　been　synthesized　under　hydrothermal　condition.　The　relationship　between　their　properties　and　structures　were　studied　by　using　FTIR,　UV-Vis　DRS　and　flurescence.　The　FTIR　showed　that　the　vibrational　frequencies　of　the　group　are　related　to　the　structure　of　the　materials.　In　UV-Vis　DRS　spectra　of　compound　I,　there　are　four　characteristic　wide　peaks　at　200,　230,　260　and　350　nm　corresponding　to　Ot→V,　Oμ→Ni,　Oμ→V　charge　transfer　and　phen＇s　π-π*,　respectively.　The　fluorescence　spectra　of　clusters　have　been　studies.　Finally,　the　quantum　chemistry　calculation　was　performed　by　Gaussian　98　program　to　explain　the　structure　characteristic　of　compound　I.