  Nucleon matters are studied based on QCD. We extract nucleon-nucleon
interaction from lattice QCD simulations in a recently developed approach, and
then derive the equations of state of the symmetric nuclear matter and the pure
neutron matter, at zero temperature, in the Brueckner-Hartree-Fock framework.
We find that QCD reproduce known features of the symmetric nuclear matter, such
as the self-binding and saturation, at some values of quark mass. We find also
that the pure neutron matter become more stiff at large density as quark mass
decrease. We apply these equations of state to neutron star and study its mass
and radius.
