Modern state-building and law-making in Ukraine at the stage of its development necessitates a very acute need for a clear mechanism for the functioning of the modern Ukrainian state, as well as all its components, first of all, institutions of state power. There is no doubt that the present dictates the urgent need for constitutional, administrative, local self-government and other planned reforms. In this list, the reform of the prosecutor's office and determination of its role and place in society, as an organ intended to protect the rights, freedoms and legitimate interests of a person and a citizen, is important. In view of this, the problems of revealing and learning the essence and content of the prosecutor's office, its appointment in the mechanism of the Ukrainian state, as well as the representation of the rights, freedoms and legitimate interests of citizens by the prosecutor in administrative proceedings are relevant both in public administration and in law science in general. The article is devoted to the disclosure of the understanding of representation as a special category for the implementation of certain legal actions by one person on behalf of another or others, the performance of duties or possession of the rights of a representative of an institution, organization, representing whose interests. Special attention is paid to the representation of the rights, freedoms and legitimate interests of citizens by the prosecutor in administrative proceedings. The rapid progress towards a rule-of-law state, in which there is actually a reliable mechanism for the protection and protection of citizens' rights and freedoms, necessarily requires a scientific analysis of the status of the prosecutor's office, the problems of its reform, the peculiarities of its activity and competence, the normative basis for guaranteeing its activities in relation to the representation of rights and freedoms and the legitimate interests of citizens by the prosecutor in administrative proceedings.