  We derived a simple metal-insulator criterion in analytical form for the
doped Mott-Hubbard materials. Its readings closely related to the orbital and
spin nature of the ground states of the unit cell. The available criterion
readings (metal or insulator) in the paramagnetic phase points to the
possibility of the insulator state of doped materials with the forbidden first
removal electron states. According to its physical meaning the result is
similar to Wilsons criterion in the itinerant electron systems. An application
of the criterion to the high-Tc cuprates discussed.
