  We present a microscopic examination for the itinerant-localized duality
model which has been proposed to understand anomalous properties of strongly
correlated systems like the heavy fermions by Kuramoto and Miyake, and also
useful to describe the anomalous properties of the high-Tc cupurates. We show
that the thermodynamic potential of the strongly interacting Hubbard model can
be rearranged in the form of duality model on the basis of renormalized
perturbation expansion of the Luttinger-Ward functional if the one-particle
spectral weight exhibits triple peak structure. We also examine the incoherent
degrees of freedom described as a ``localized spin'' and show on the basis of
the pertubation expansion that there exists commensurate superexchange-type
interaction among the ``localized spins''.
