The compositional depth profile of GexSi1-x/Si strained layer superlattice has been obtained by AES combined with argon ion sputtering, which indicates the concentrations of Ge and Si vary with depth periodically. The secondary electron image shows some periodic pattern consisting of alternate bright and dark bands around the center of the sputtered crater. The characteristics of Auger depth profile as a method for superlattice structure analysis, as well as its limitations, are discussed.