The nano-granular magnetic films were investigated using the micromagnetics method in this paper. The nano-granular magnetic film model studied consisted of an aggregate of 122 spherical nano-granules with an fcc structure. The computational results showed that the effect of the dipolar interaction of the system on the static magnetic structure is remarkable, while the effect of exchange interaction is indistinc. The frequency dependent permeability spectra of granular films with different volume ratio of magnetic components were simulated and the percolation phenomena of nanostructural magnetic films were extensively analyzed. Thus, the percolation threshold of the system studied was obtained according to the effective medium theory. Furthermore, the design of nano-granular magnetic films with large magnetic losses were carried out.