Two new molybdenum–vanadium polyoxometalate tri-supported transition metal complexes [Cu(2,2 ′-bipy)] [Cu(2,2 ′-bipy) 2] 2[PMo 8V 6O 42]· nH 2O ( n = 1.5 ( 1) and n = 2 ( 2); 2,2 ′-bipy = 2,2 ′-bipyridine) have been hydrothermally synthesized and characterized by elemental analyses, IR, XPS and single-crystal X-ray diffraction analyses. Both compound 1 and compound 2 contain molybdenum–vanadium polyoxometalates, each of which support one [Cu(2,2 ′-bipy)] 2+ cation and two [Cu(2,2 ′-bipy) 2] 2+ cations, respectively. The difference between compound 1 and compound 2 is that the polyoxoanion of 1 is a bi-capped α-Keggin cluster and that of 2 is a bi-capped pseudo-Keggin one. Studies of magnetic properties indicated the presence of ferromagnetic behaviors for compounds 1 and 2.