Through tuning the length of flexible bis(triazole) ligands and different metal ion coordination geometries, four Wells-Dawson polyoxoanion-based hybrid compounds, [Cu-6(btp)(3)(P2W18O62)] center dot 3H(2)O (1) (btp = 1,3-bis(1,2,4-triazol-1-yl)propane), [Cu-6(btb)(3)((P2W18O62) center dot 2H(2)O (2), [Cu-3(btb)(6)(P2W18O62)] center dot 6H(2)O (btb = 1,4-bis(1,2,4-triazol-1-yl)butane) (3), and [Cu-3(btx)(5.5)((P2W18O62) center dot 4H(2)O (btx = 1,6-bis(1,2,4-triazol-1-yl)hexane) (4), were synthesized and structurally characterized. in compound 1, the metal-organic motif exhibits a ladder-like chain, which is further fused by the ennead-dentate [P2W18O62](6-) anions to construct a 3D structure. In compound 2, the metal-organic motif exhibits an interesting Cu-btb grid layer, and the ennead-dentate polyoxoanions are sandwiched by two Cu-btb layers to construct a 3D structure. Compound 3 exhibits a (4(2).6(2).8(2)) 3D Cu-btb framework with square and hexagonal channels arranged alternately. The hexa-dentate polyoxoanions incorporate only into the hexagonal channels. In compound 4, there exist two sets of (6(1).10(2))(2)(6(1).8(2).10(3)) 3D Cu-btx frameworks to generate a 2-fold interpenetrated structure into which the penta-dentate polyoxoanions are inserted to construct a 3D structure. The structural analyses reveal that the length of flexible bis(triazole) ligands and metal ion coordination geometries have a synergic influence on the structures of this series. To our knowledge, they have the highest connectivity for the Wells-Dawson polyoxometalate coordination polymers to date.