  The evolution equations of the Yukawa couplings and quark mixings are derived
for the one-loop renormalization group equations in the 5D Minimal
Supersymmetric Standard Model on an {$S^1 / Z_2$} orbifold. Different
possibilities for the matter fields are discussed such as the cases of bulk
propagating or brane localised fields. We discuss in both cases the evolution
of the mass ratios and the implications for the mixing angles.
