Experimental studies of the relaxation of electrophysical parameters of SOI structures with different doses of hydrogen implantation after exposure to stationary X-ray radiation are presented. Investigation of high-frequency CV characteristics and pseudo-MOS transistors made it possible to obtain information about the accumulated charge, the density of surface states, mobility of carriers. The impurity composition and depth profile of hydrogen concentration were determined by the SIMS method. Structural perfection of the layers and interfaces was evaluated using the XRR and XRD methods. A different nature of the relaxation dependence and the recovery time of the electrophysical parameters for SOI structures with different doses of hydrogen implantation are recorded. The values of mobility and charge density are higher for the structure with a lower hydrogen implantation dose. Keywords: Ion implantation, silicon on insulator, radiation resistance, X-ray diffraction, pseudo-MOS transistor, residual hydrogen, SIMS.