We study the dynamical symmetry breaking in the gauge-Higgs unification of the 5D theory compactified on an orbifold, S1/Z2. This theory identifies Wilson line degrees of freedoms as ``Higgs doublets''. We consider SU(3)c×SU(3)W
Nearby in the stack
and SU(6) models with the compactification scale of order a few TeV. The gauge symmetries are reduced to
SU(3)c×SU(2)L×U(1)Y
and
SU(3)c×SU(2)L×U(1)Y×U(1)
, respectively, through the orbifolding boundary conditions. We estimate the one loop effective potential of ``Higgs doublets'', and find that the electro-weak breaking is realized through the radiative corrections when there are suitable numbers of bulk fields possessing the suitable representations. The masses of ``Higgs doublets'' are