Fine (oscillating) structure (FS) in the elastically scattered electron spectra (ESES) [O. Bondarchuk, S. Goysa, I. Koval, P. Melnik, M. Nakhodkin, Surf. Sci. 258 (1991) 239; O. Bondarchuk, S. Goysa, I. Koval, P. Melnik, M. Nakhodkin, Surf. Rev. Lett. 4 (1997) 965] was used to investigate surface structure of the SiOx (0 <= x <= 2). SiOx surface with different stoichiometry was prepared by implantation of 500 eV oxygen ions into a silicon wafer. Fourier transformation of the FS ESES contains one peak at 2.32 angstrom for Si, two peaks at 1.62 angstrom and 2.65 angstrom for a-SiO2 and three peaks centered at 1.6-1.7 angstrom, 2.1-2.2 angstrom and 2.65-3.04 angstrom for SiOx. Peaks at 1.62 angstrom and 2.65 angstrom are assigned to Si-O and O-O nearest distances correspondently. Ratio of the area under the peak at 2.65 A to the area under the peak at 1.62 A turned out to be not constant but grows linearly with the composition parameter x. The latter is considered to prove validity of the Random Bond Model to describe short-range order on the surface of non-stoichiometric silicon oxide. (C) 2009 Elsevier B.V. All rights reserved.