Abstract: The research subject is administrative activity of authorities in Russia and some other countries. The author focuses on the formation and development of administrative activity as one of the key types of public activity. The author considers the views of scholars of different periods on the “administrative activity” concept and the experience of formalization of administrative activity in legislation. Special attention is given to the correlation between administrative activity and public administration and the influence of the administrative reform on the modern state of administrative activity. The author uses general scientific and specific research methods including historical, comparative-legal and the method of dogmatic interpretation of statutory acts. The author formulates the idea that administrative activity is one of the key forms of public activity; at the present time, administrative activity is usually studied within particular branches, and administrative activity itself needs to be conceptually and theoretically substantiated. Such conceptual and theoretical substantiation of administrative activity by law enforcement bodies and special services requires special attention. 

Abstract: In the conditions of terrorist activity increase, its geography expansion and organization enhancement there is an objective need for the increase of effectiveness of preventive measures. As it is stated in the Anti-terrorist strategy of the Russian Federation, the realization of legislative measures is of primary importance in terrorism prevention. Taking into account the possibility of a flexible and quick realization of administrative law provisions and the preventive character of these provisions, administrative-legal measures should be assigned one of the leading parts among the complex of preventive measures. The article reveals the system of the most effective administrative-legal measures of terrorism prevention which can be used by law-enforcement agencies and special services. The proposed system of administrative-legal measures is based on the analysis of content and practice of use of the conceptual documents and legal provisions regulating the issues of terrorism prevention and administrative-legal mechanisms implementation. The author creates an easy-to-use model of the system of the most effective administrative-legal measures of terrorism prevention. Taking into consideration the obvious need for expansion of use of administrative-legal measures of terrorism prevention, the systematization of these legal measures takes of special significance and can promote the effective activities of special services and law enforcement agencies in this sphere.