  We suggest simple models which produce the suitable fermion mass hierarchies
and flavor mixing angles based on the 6 dimensional N=1 supersymmetric SO(10)
grand unified theory compactified on a $T^2/(Z_2 \times Z_2')$ orbifold. We
introduce 6D and 5D matter fields, which contains the 1st and 2nd generation
matter fields as the zero modes, respectively. The 3rd generation matter fields
are located on a 4D brane. The Yukawa couplings for bulk fields are suppressed
by volume factors from extra dimensions. The suitable fermion mass hierarchies
and flavor mixings are generated by the volume suppression factors.
