Abstract. Given article is devoted to investigations performed within the framework of the ITER Project in Kazakhstan and to support of studies of characteristics of structural materials of DEMO reactor. Main direction of the activity was investigation of hydrogen isotope interaction with prospective structural materials for fusion reactor: stainless steels, vanadium alloys, low-activated steels such as MANET or F82H, beryllium, LiPb eutectics and Li containing ceramics. The basic parameters of hydrogen isotope interaction with the specified structural materials have been determined by permeation and thermo-stimulated gas release techniques in the process of reactor irradiation. To carry out the research activity in the support of ITER Project and for personnel training, Kazakhstan develops tokamak for material studies (KTM). The design of this reactor follows this basic configuration: mega-ampere spherical tokamak with low aspect ratio, plasma confinement time of approximately five seconds and parameters of plasma sufficient to perform investigations of prospective structural materials as a support of ITER project.