The article analyzes the procedural norms of law that regulate the issue of representation in the administrative proceedings of Ukraine. Based on the analysis, it was concluded that the institution of representation in the administrative process has undergone significant changes in connection with the judicial reform. During the administration of justice, courts of administrative jurisdiction decide the issue of participation in the case of a representative in the presence of conflicting legislation, which, in turn, creates ambiguity in judicial practice. Attention was drawn to the fact that the Code of administrative proceedings of Ukraine, in the new version, classified the bodies and persons who have the right to apply to the court in the interests of other persons to the participants of the case. In turn, from «persons participating in the case», «representatives» are included in a separate category of participants in the legal process, which is established in the norms of a special paragraph of the Code. A new term «self-representation» was also introduced, which is inconsistent with the norms of the Constitution of Ukraine. At the same time, self-representation distinguishes representation under the law in the presence of family relations and representation under a contract, which can be carried out by a lawyer or a natural person who has administrative procedural capacity, in cases of minor complexity and in other separate cases defined by law. It is emphasized that the procedural law does not clearly demarcate the powers in the judicial process of bodies and persons who are granted the right to appeal to the court in the interests of other persons, and legal representatives. At the same time, both of them participate in the legal process based on the prescription of the law, and the purpose of their participation is completely the same. At the same time, it is stated that self-representation is a new type of representation, which is different from representation under a contract or law in the generally accepted sense and which needs to be refined at the legislative level. It was noted that legislative changes in the institution of self-representation essentially helped to bypass the norms of the Constitution on exclusive representation by lawyers of individuals and subjects of power in court. As a result, it was concluded that the legal regulation of the participation of the representative, including the self-representative, in the administrative process requires further scientific analysis and legislative improvement. Key words:administrative court, participants in the legal process, representative, self-representative, norms of procedural law.