The essence of administrative and legal regulation of the activities of the subjects of the national cybersecurity system of Ukraine has been established, which consists in building an effective system for ensuring cybersecurity and requires from the state bodies of Ukraine a clear legal definition of the principles of state policy in this area and an advanced response to dynamic changes taking place in the world in the field of cybersecurity. The classifier of threats to the security of information resources has been improved, which, in contrast to the existing ones, is based on a synergetic model of threats, which allows to classify threats by security components, types of services, and hierarchy levels of the infrastructure of automated systems, to assess the synergy and hybridity of threats to information security, cybersecurity, information security, and the likelihood of their impact on the security of information resources. It has been proved that the choice of specific means and ways of ensuring the cybersecurity of Ukraine is conditioned by the need to take timely measures adequate to the nature and scale of real and potential cybernetic threats to the vital interests of a person and citizen, society and the state. The purpose of the cybersecurity system of Ukraine has been clarified. The task of the cybersecurity system is to create the necessary conditions in cyberspace, under which it is possible to achieve national goals and realize the interests, tasks, and goals of its elements.