Kβ-to-Kα X-ray intensity ratios of Ti and Ni have been measured in pure metals and in alloys of Ti x Ni 1− x (x=0.7, 0.6, 0.5, 0.4 and 0.3) following excitation by 22.69keV X-rays from a 10mCi 109 Cd radioactive point source. The valence-electron configurations of these metals were determined by corporation of measured Kβ-to-Kα X-ray intensity ratios with the results of multiconfiguration Dirac–Fock calculation for various valence-electron configurations. Valence-electron configurations of 3d-transition metals in alloys indicate significant differences with respect to the pure metals. Our analysis indicates that these differences arise from delocalization and/or charge transfer phenomena in alloys. Namely, the observed change of the valence-electron configurations of metals in alloys can be explained with the transfer of 3d electrons from one element to the other element and/or the rearrangement of electrons between 3d and 4s, 4p states of individual metal atoms.