  A realization of heavy fermion state is investigated on the basis of two-band
Hubbard model. By means of the slave-boson mean-field approximation, it is
shown that for the intermediate electron density, n_e=1.5, the inter-band
Coulomb repulsion U strongly emphasizes initially small difference between
bands, and easily stabilizes integral valence in the lower band. As a result, a
strong renormalization takes place in the lower band and the mixing strength
between two bands. It gives rise to a sharp peak at the Fermi level in the
quasiparticle density of states, as that obtained in the periodic Anderson
model. In contrast to a simple insight that the Hund's-rule coupling J reduces
the characteristic energy, it turns out to be almost irrelevant to the
renormalization for J<U. The required conditions are suitable for LiV_2O_4, the
first observed heavy fermion compound in transition metal oxide.
