Nature of the characteristic electron energy losses in the second electron emission spectra from the ternary Co-Cr-Mo alloy surface are studied in the low energy range of the primary electron energy E-0. The main types of losses were found: surface and bulk plasmons and their hybrid modes, interband transitions and ionization losses. For Co, Cr, Mo and Co-Cr-Mo alloy the experimental values of the plasmon energy were established to be less than it was predicted by free-electron gas model. Excess of conductive electrons in the surface layers for Co, Cr and Mo was observed by dependence of the surface plasmon dispersion from E-0, while for Co-Cr-Mo alloy the situation is quit opposite. Such behavior is explained by the complex phase structure of the ternary alloy. The analysis of intensity lines of plasmons from E0 showed deeply changed alloy profile. Ionization Spectroscopy was used for studying the alloy elements distributing on the depth. Mo atoms preferred segregation in the outermost layers of Co-Cr-Mo alloy and enrichment with Cr competitive atoms in underlayers is displayed. (C) 2008 Elsevier B.V. All rights reserved.