Abstract: Ionic liquid-like polyoxometalates (POM-IL),[PyPS]_nH_3-nPW₁₂O₄₀·xH₂O(n=1,2,3),were synthesized by using pyridine,1,3-propanesultone and tungstophosphoric acid as raw materials. The compounds were characterized by means of FT-IR,UV-Vis,¹H NMR and elementary analyses. The results showed that Keggin structure of POM was kept and there were character bands of pyridyl propylsulfonic acid in the POM-IL salts. All prepared compounds possess melting-points above 130℃ and the melting-points decreased with the increase of the organic component. Furthermore,the photocatalytic performances of these POM-IL samples for the degradation of aqueous dyes were investigated.Under UV irradiation,the samples with n=1 and 2 showed similar photocatalytic activities to that of tungstophosphoric acid for the degradation of methyl orange. Under visible light,all POM-IL salts exhibit the same photocatlytic activities which are superior to tungstophosphoric acid for the degradation of isatin.Therefore,all these POM-IL salts might be promising photocatalysts for the degradation of some dyes under visible light.