Permeability through media having various structures has been studied theoretically. We consider loose porous media, like fibrous materials, and media with a localized pore network, like fractured rocks. We model complicated porous structures by using assemblage of spherical particles. The calculations of permeability are performed by the Stokesian dynamic approach, which enables us to derive fluid motion in the presence of many particles. The Ewald summation technique is employed to represent infinite and finite particulate beds. In the infinite bed where the particles exist endlessly in space, we investigate how the internal structure of the media affects permeability. The results indicate that permeability significantly depends on internal structure, particularly the void geometry. In the finite bed where the particles form a bed with finite thickness, we discuss permeability variance due to the presence of ends. It is found that permeability greatly varies in the vicinity of ends owing to the anisotropy of the flow field, which arises from the presence of ends.