  The braneworld cosmological model was constructed by embedding a 3-brane into
a higher dimensional bulk background geometry and the usual matter of our
universe was assumed to be confined in the brane while the gravity can
propagate in the bulk. By considering that the bulk geometry is anisotropic,
after reviewed the separable solution for the bulk metric and the result that
the anisotropic property of the bulk can support the perfect fluid kind of the
matter in the brane, we develop a formalism of the cosmological perturbation
for this kind of anisotropic braneworld model. As in isotropic case, we can
also decompose the perturbation into scalar, vector and tensor modes, we find
that the formalism for the anisotropic braneworld cosmological perturbation are
very different from the isotropic case. The anisotropic effect can be reflected
in the tensor modes which dominated the cosmological gravitation waves.
Finally, we also discussed the perturbed Einstein equations governed the
dynamics of the bulk geometry and the brane with the junction conditions.
