(1) High Temperature Nuclear Matter: Physics of High-Energy Heavy-Ion Collisions

Recent development of high-energy heavy-ion physics has been reviewed
from a view point of the hadronic matter equation of state in relation with
the hadronic degrees of freedom. At AGS energies (E = 10 A GeV), softening
of matter is realized, and it is explained in the context of reduction of 
repulsive nuclear force at high momenta and the resonance hadron and string
formation. At RHIC energies, recent data seem to show "re-hardening".
This re-hardening might signal the bulk QGP formation.

(2) High Density Nuclear Matter: Strangeness in Neutron Stars

Roles of strange hadrons in high density nuclear matter in the neutron star
core are reviewed. In dense neutral matter, since neutron and electron 
chemical potentials become large, negatively charged baryons (<-> n + e-)
are favored. Therefore, one of the most important ingredient here is 
the interaction of nucleons with negative Sigma and negative Cascade baryons.
After the explanation of chemical equilibrium and the TOV equation, 
calculated particle fractions of electons, muons, nucleons and hyperons are 
shown with different choice of hyperon-nucleon interactions. It is emphasized
that microscopic calculations of hyperonic matter EOS are very important.