The specific properties of tubular and fullerenlike silicon nanoparticles depend on theirs electronic structure, which is directly related to the surface geometry. Using density functional approach, a novel dual nature of the surface structure of silicon nanotubes which depends on the type of nanotube have been revevaled. The rippled form of the surface has shown to be a favorable one for (n, n) type structure and the most stable form for (n, 0) Si NT is the nanotube with a smooth-walled graphene-like surface. The phenomenon is explained by the relative position of the non-hybridized p orbitals on the surface.