  We study the manganese oxides from the viewpoint of the strongly correlated
doped Mott insulator. The magnetic ordering and the charge transport are
governed by the orbital degrees of freedom, and their dimensionality is
controlled by the anisotropic transfer integrals between the $e_g$ orbitals. As
x increases the magnetic structure is predicted to change as $A \to F \to A \to
C \to G$ (F: ferromagnet, A: layered antiferromagnet, C: rod-type
antiferromagnet, G: usual antiferromagnet), in agreement with experiments.
Especially the orbital is aligned as $d_{x^2-y^2}$ in the metallic A state,
which explains the quasi 2D transport and no canting of the spin observed
experimentally. Next we discuss the ferromagnetic state without the orbital
ordering due to the quantum fluctuation. Here the interplay between the
electron repulsion U and the Jahn-Teller electron-phonon interation $E_{LR}$ is
studied with a large d model. In addition to this strong correlation, we
propose that the dynamical phase separation could explain the specific heat as
well as the various anomalous physical properties, e.g., resistivity,
photo-emission, etc.
