  We study the influence of the symmetry energy of the equation of state on the
thermal evolution of protoneutron stars and the properties of supernova
neutrinos by the numerical simulations after the protoneutron stars are formed.
As for the equation of state (EOS) of nuclear matter, we take two EOS's with
different symmetry energies obtained by the relativistic mean field theory. We
find the symmetry energy plays the essential role on the evolution of lepton
profiles and the neutrino fluxes.
