By combination of heteropolymolybdates and metal-Schiff-base complexes, two new organic-inorganic hybrid compounds {Mn(salen)(2)(H(2)O)(2)[AlMo(6)(OH)(6)O(18)]}[arg]·16H(2)O (1) and {Mn(salen)(2)(H(2)O)(2)[CrMo(6)(OH)(6)O(18)]}[arg]·11H(2)O (2) (salen = N,N'-ethylene-bis(salicylideneiminate) have been successfully isolated. Compounds 1 and 2 were structurally characterized by elemental analyses, IR spectra, thermogravimetric analysis, and single-crystal X-ray diffraction. To the best of our knowledge, compounds 1 and 2 represent the first single-crystal structures of metal-Schiff-base decorated polyoxometalates (POMs) compounds. Photocatalytic experiments indicated that both 1 and 2 exhibit high catalytic activity for photodegradation of RhB with UV irradiation. In addition, the magnetic properties of 1 were also investigated.