Four structurally intriguing members of a new family of lanthanide (Ln)-containing organophosphonate-functionalized polyoxotungstates with the general formula K2[Ln(H2O)4(AsW9O33)(W2O3)(O3PCOHCH3PO3)Ln(H2O)7]2·15H2O [Ln = Ce (1Ce), Nd (2Nd), Sm (3Sm) and Eu (4Eu)] were directly isolated by controlling the reaction parameters and well established by single-crystal X-ray diffraction, PXRD analyses, IR spectra, elemental analyses, TG and EDX analyses. All the four three-dimensional frameworks consist of the S-shaped inorganic building block {[(AsW9O33)(W2O3)]2}, two organophosphonate groups {O3PCOHCH3PO3} and four Ln ions. The magnetic properties of the four compounds and the solid-state photoluminescence properties of 2Nd, 3Sm, and 4Eu were also fully investigated.