Dynamical symmetry breaking on a brane with bulk gauge theory

We analyze a structure of dynamical chiral symmetry breaking in orbifold gauge theories with matter fields (fermions) on the fixed point. We find that the boundary chiral phase structure of QED and QCD on the orbifold is quite nontrivial depending on the bulk constitution, and we claim that particular attention should be given to the dynamically generated masses in various kinds of phenomenological orbifold models.