The relevance of this topic is determined to the fact that during the introduction of the legal regime of martial law, the activities of public authorities, in particular the executive, have certain peculiarities/ On February 24, 2022, the President of Ukraine, based on the proposal of the National Security and Defense Council of Ukraine, in accordance with clause 20, part 1 of Article 106 of the Constitution of Ukraine and the Law of Ukraine "On Legal Martial Law" introduced the martial law regime in connection with the invasion of the Russian Federation in Ukraine, which stipulate for changes in the work of executive authorities, in particular the Cabinet of Ministers of Ukraine, and cause to the formation of military administrations. The purpose of the article is to study of the legal nature of the martial law regime and the procedure for its introduction, to reveal the main peculiarities of the activities of the executive authorities, in particular the Cabinet of Ministers of Ukraine and military administrations, during the introduction of the martial law regime, as well as the study of their interaction with each other. Achieving the outlined purpose became possible for the application of the used complex of methods of scientific knowledge, in particular, the dialectical method (for comprehensive knowledge of the nature of the legal regime of martial law and its conduct, determination of the order of formation and functions of military administrations, analysis of the peculiarities of the activity of the Cabinet of Ministers of Ukraine), the formal-legal method (for establishing the content of legal norms), the formal-logical method (to identify deficiencies in national legal regulation), the comparative-legal method (to study the experience of other countries and determine the procedures for introducing the legal regime of martial law), communicative method (to determine the influence of the Cabinet of Ministers of Ukraine on military administrations and to analyze the directions of their interaction). The review of the current legislation of Ukraine and the legislative acts of other countries regarding the procedure for conducting and legal regulation of the martial law regime are analyzed. The nature of the emergence of military administrations has been analyzed, and it has been found that they are temporary bodies of executive power for the period of martial law. It is noted that is placed on their powers to ensure law and order and support the country's defense capability in the settlements under their control. The peculiarities of the activity of the Cabinet of Ministers of Ukraine during the period of martial law were studied. The directions of interaction between the military administrations and the Cabinet of Ministers to ensure the functioning of all areas of the country's life have been clarified. According to the results of the study on avoiding any divergence in law enforcement approaches in the future, separate proposals were made to strengthen the accountability of the military administrations of the Cabinet of Ministers of Ukraine.