In this paper the results of research of influence of laser emission on electrophysical and structural parameters of SiO2/Si system are given. Research samples were irradiated with optical fiber YLP-laser (λ=1,06 μm) with 250ns pulse length. Power of emission in impulse was (2-4) - 7,13 Wt/sm2 . As experimental sample thermal oxidated silicon base KEF-4,5 was used, which crystallographic plane was similar to (100). As a result of experiments it is shown that laser irradiation of Si/SiO2 system can form SiO2+silicon nanoclusters system on silicon film. Nano-engineering of SiO2/Si system is accompanied by essential changing of electrophysical properties of initial MOS structures.© (2010) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.