By changing the solvents, three polyoxometalate(POM)-based supramolecular hybrids, [Co;L;][SiW;O;]·17 H;O(1),[Co;L;(H;O);][SiW;O;].2 EtOH·2 H;O(2) and [Co;L;][SiW;O;]·9 DMA·6 H;O(3), have been synthesized under hydrothermal or solvothermal conditions. All three hybrids show various supramolecular structures, which contain two kinds of different metal-organic motifs. A kind of metal-organic cationic cage [Co;L;];is formed in the presence of H;O for 1, DMA/H;O for 3, and a metalorganic cationic circle [Co;L;];is constructed in the presence of EtOH/H;O for 2. That is to say, the solvents show a key role in tuning the architectures of metal-organic fragments and the final POM-based supramolecular structures. The adsorption properties of 1-3 for different organic dyes have also been investigated.