Fullerenes are spherical molecules composed of pentagons and hexagons. Endohedral fullerenes, which possess inner space capable of encapsulation of variable clusters and molecules, have generated considerable recent research interest. By introducing CO₂ as the reactive gas source, the synthesis of extensive families of oxide clusterfullerenes was demonstrated in this study. Sc₂O@C₇₀, Sc₂O@C_2n (n=38-42) and mixed dimetaillic fullerenes ScGdO@C₈₂, have been isolated and characterized by mass spectrometry, UV−Vis−NIR absorption spectroscopy, cyclic voltammetry, ⁴⁵Sc NMR, DFT calculations and single crystal X-ray diffraction. Crystallographic studies unambiguously assigned the cage structures of these metallic oxide cluster fullerenes to Sc₂O@C₂(7892)-C₇₀，Sc₂O@T_d(19151)-C₇₆, Sc₂O@D_3h(5)C₇₈, Sc₂O@C_2v(3)C₇₈, Sc₂O@C_2v(5)-C₈₀ and Sc₂O@C_3v(8)-C₈₂. Among them, Sc₂O@C₂(7892)-C₇₀ presents the first detailed structural analysis of is a Non-IPR C₇₀ endohedral fullerene and Sc₂O@T_d(19151)-C₇₆ is the first tetrahedral fullerene cage characterized by single crystal X-ray diffraction. The comparative crystallographic studies of these novel structures also demonstrate that Sc₂O cluster is flexible inside the carbon cage and the Sc-O-Sc angle varies with the different cage size or symmetry. The discovery and characterization of these novel structures provide examples of stabilization of new endohedral fullerene structures resulting from the combined effect of electron transfer and the geometrical fit between Sc₂O cluster and the cage.