  We discuss anomalous Higgs interactions in the scenario of gauge-Higgs
unification. In the scenario Higgs originates from higher dimensional gauge
field and has a physical meaning as AB phase or Wilson loop. As its inevitable
consequence, physical observables are expected to be periodic in the Higgs
field. In particular, the Yukawa coupling is expected to show some periodic and
non-linear behavior as the function of the Higgs VEV. For a specific choice of
the VEV, the Yukawa coupling of KK zero mode fermion even vanishes. On the
other hand, the Yukawa coupling is originally provided by gauge interaction,
which is linear in the Higgs field. We discuss how such two apparent
contradiction about the non-linearity of the Yukawa coupling can be reconciled
and at the same time how these two "pictures" give different predictions in the
simplest framework of the scenario: SU(3) electroweak model in 5-dimensional
flat space-time with orbifolding. The deviation of the Yukawa coupling from the
standard model prediction is also calculated for arbitrary VEV. We study
"$H$-parity", which guarantees the stability of the Higgs for a specific choice
of the VEV. Also discussed is the Higgs interaction with $W^\pm$ and $Z^0$. It
turns out that in our framework of flat space-time the interaction does not
show deviation from the standard model prediction, except for the specific case
of the VEV.
