A series of 3D porous lanthanide-substituted polyoxometalate frameworks, Na-2[Ln(2)(H2O)(11)](2)[Ln(3)(H2O)(3)(alpha-SiW11 O-39)(2)](2)center dot 69H(2)O (1-Ln, Ln = Sm, Eu, Gd, Tb, and Dy), are built from novel hexadecahedral {Ln(6)W(8)O(28)} heterometallic cage-shaped clusters. Intriguingly, every tetrameric {[Ln(3)(H2O)(3)(alpha-SiW11O39)(2)](2)}(14-) cage-cluster is linked with another eight tetrameric cage-clusters by Ln(3+) cations, leading to a novel 3D inorganic porous framework, which exhibits good thermal and chemical stability, excellent water vapor adsorption capacity, and moderate proton conductive properties. Furthermore, the solid state luminescence spectra demonstrate that 1-Sm, 1-Eu, 1-Tb, and 1-Dy display the lanthanide characteristic emission bands. The temperature-dependent magnetic susceptibility indicates that there are antiferromagnetic interactions in 1-Tb and 1-Dy.