  Though the mass of Higgs particle is the parameter determined by the
experiment in the standard model (SM), SUSY models have rather predictive power
for the lightest Higgs mass, and its upper bound in some SUSY models are close
to the observable region in LEP2. The upper bound of the lightest Higgs mass is
analysed systematically on the basis of the $CP$ violation in the minimal and
the next minimal supersymmetric standard model (MSSM and NMSSM). In the
explicit $CP$ violation case, the mass bound is large around $130 \sim 160$ GeV
in both models. In the spontaneous $CP$ violation case induced by the radiative
effects, the lightest Higgs mass upper bound is about $52$ GeV and sum of two
light neutral Higgs should be around $O$(100 GeV) in the NMSSM in contrast to
the one in the MSSM which implies about 6 GeV. This model gives the interesting
predictions for the neutron electric dipole moment.
