The article is devoted to the problems of organizing the activities of the National Police as a subject of the security and defense sector. The analysis of the scientific works of the scholars who were engaged in research within the framework of this issue made it possible to formulate the author’s definition of the concept of the security and defense sector. It was established that it is necessary to study, analyze and practically apply the experience of international institutions, organizations (NATO, EU, OSCE) of democratic European countries in order to improve national legislation and eliminate gaps, taking into account the experience of practical activities of police officers in the field of security and defense, to update the legal framework for ensuring the functioning of the national security system. The powers of the National Police as a subject of the security and defense sector is considered. It has been established that they can be of a general nature, that is, aimed at protecting the national interests of Ukraine from internal and external threats, ensuring the independence of the state and the protection of state sovereignty, as well as the territorial integrity of Ukraine, prevention of threats to national security, and more. It has been proven that a mandatory condition for a police officer during the performance of assigned tasks is compliance with the principles enshrined in international and national regulatory legal acts. Among the general principles, the following are distinguished: the principle of the rule of law, the principle of respect for human rights and freedoms, the principle of legality, the principle of openness and transparency, the principle of political neutrality, the principle of interaction with the population on the basis of partnership, the principle of continuity. It is proposed to make changes to the normative legal acts, namely: in the Law of Ukraine “On the National Police” to define the police as a subject of the security and defense sector, and in the Law of Ukraine “On the National Security of Ukraine” to define specific tasks of national security that require its provision by the police. This will make it possible to improve the role of the National Police of Ukraine as a subject of SDS.