  The mass matrix forms of quarks and leptons are discussed in theory with
permutation flavor symmetry. The structure of scalar potential is analyzed in
case that electroweak doublet Higgs fields have non-trivial flavor symmetry
charges. We find that realistic forms of mass matrices are obtained dynamically
in the vacuum of the theory, where some of Higgs bosons have vanishing
expectation values which lead to vanishing elements in quark and lepton mass
matrices. Mass textures are realized in the true vacuum and their positions are
controlled by flavor symmetry. An interesting point is that, due to the flavor
group structure, the up and down quark mass matrices are automatically made
different in the vacuum, which lead to non-vanishing generation mixing. It is
also discussed that flavor symmetry is needed to be broken in order not to have
too light scalars. The lower bounds of Higgs masses are derived from the
experimental data of flavor-changing rare processes such as the neutral K meson
mixing.
