  The structure of Yukawa coupling matrices is investigated in type IIA
T^6/(Z_2 x Z_2) orientifold models with intersecting D-branes. Yukawa coupling
matrices are difficult to be realistic in the conventional models in which the
generation structure emerges by the multiple intersection of D-branes in the
factorized T^6 = T^2 x T^2 x T^2. We study the new type of flavor structure,
where Yukawa couplings are dynamically generated, and show this type of models
lead to nontrivial structures of Yukawa coupling matrices, which can be
realistic.
