It is impossible to directly analyze the microstructure of spin-valve multilayers based on Ni,F,Cu and Mn by a conventional X-ray diffraction technique because the lattice parameter and atomic sattering factor sof them are very close.To solve this problem, we use an x-ray anomalous diffraction technique to characterize the microstructures of the [Ni80Fe20/Fe50Mn50]15 and [Ni80Fe20/Cu]15 superlattice systems.The results show that more diffraction peaks and higher internsity in the reflectivety profile are observed when the incident energy is close to the absorption edge of the lighter element(Mn) in [Ni80Fe20/Fe50Mn50]15 multilayer systems and to the absorption edge of the heavier element (Cu) in the [Ni80Fe20/Cu]15 multilayer systems.The interface and periodic structure of [Ni80F20/Fe50Mn50]15 are more perfect than that of the [Ni80Fe20/Cu]15 superlattices.The above results are disussed in this paper.