Research on the MgB2/Ni and MgB2/B multilayer films fabricated by an electron beam (EB) evaporation technique have been extensively carried out. The critical current density, J(c) of MgB2/Ni and MgB2/B multilayer films in parallel fields has been suggested to be higher than that of monolayer MgB2 film due to introducing the artificial pinning centers of nano-sized Ni and B layers. Nanostructure characterization of the artificial pinning centers in the multilayer films were examined by transmission electron microscopy (TEM) and scanning TEM (STEM-energy dispersive X-ray spectroscopy (STEM-EDS))-EDS to understand the mechanism of flux pinning. The growth of columnar MgB2 grains along the film-thickness direction was recognized in the MgB2/Ni multilayer film, but not in the MgB2/B multilayer film. Nano-sized Ni layers were present as crystalline epitaxial layers which is interpreted that Ni atoms might be incorporated into the MgB2 lattice to form (Mg, Ni)B-2 phase. On the other hand, nano-sized B layers were amorphous layers. Crystalline (Mg, Ni) B-2 layers worked more effectively than amorphous B-layers, providing higher flux-pinning force that resulted in higher J(c) of the MgB2/Ni multilayer film than the MgB2/B multilayer film. (C) 2013 Elsevier B. V. All rights reserved.