A new effective method of electron microprobe yrating spectroscopy is applied to the experimental investigation of the A1 L2.3 (+Ni M2,3) emission band of some nickel-aluminium alloys. The compositional (or structural) changes in the spectra are compared with the theoretical band structure and X-ray intensity calculations. The observed variations in the spectrum profile may be attributed to the charge transfer between the component atoms and the hybridization of s and d electronic states in the valence band.