  We study moduli stabilization of the F-theory compactified on an elliptically
fibered Calabi-Yau fourfold. Our setup is based on the mirror symmetry
framework including brane deformations. The complex structure moduli dependence
of the resulting 4D N=1 effective theory is determined by the associated
fourfold period integrals. By turning on appropriate G-fluxes, we explicitly
demonstrate that all the complex structure moduli fields can be stabilized
around the large complex structure point of the F-theory fourfold.
