In the article are analyzed many sides of security of informational space as an important element of state security. Informational security means assuring informati- onal space and it involves informational-technological component besides informati- onal-psychological one. Foreign influence on public opinion and mentality could be done using many efficient methods. Manipulation of public opinion could be applied by controlling national mass media as well as by re- broadcasting of foreign chan- nels in the national territory. Proper regulation of mass media functioning, according national interests, is closely related and organically depend on intensity of informa- tional globalization process spreading, as well as on the level of mediatic culture of population.