The article is devoted to the identification of subjects, which, under the conditions of administrative and legal reform and changes of the guidelines in the relations between the state and the citizen, carry out public administration. Emphasis is placed on the sphere of relations that cover the essence of public administration. It is proved that the effectiveness of administrative law through the lens of governance is doubtful and does not fully meet the requirements of the development of public relations. Therefore, it is necessary to return to the educational ideas of the functioning of the state and its interaction with citizens, which has a manifestation in public, not state; in administration, not government. The authors substantiate that public administration is the activity of public authorities, which manifests itself in a concerted influence on specific public relations by means of specific methods, tools, forms and aims to secure public interests. The relation between the concepts of "subject of public administration" and "public management" is investigated. The proposals of the leading Ukrainian administrative scientists regarding the essence of the category of "public management" are analyzed and the reasons for the dualism of approaches to its definition in the Ukrainian administrative and legal doctrine are revealed. In addition, the subjects of public administration are classified according to their competence, scope, functions, and objectives of public administration. The subject of the research is the subjects of public administration and their functions in administrative law. The purpose is a study of the institutional constituent of public administration and defining changes experienced by governing entities as a result of reformatting the concept of relations between the state and society in Ukraine. Methodological basis of the research is a set of methods and techniques of scientific knowledge. The methodological construction is based on a systemic analysis that determined its directions. The systemic approach in some issues was supplemented by the axiological (ideological) approach. Empirical methods such as observation, description, comparison, inductive generalization were used to identify tendencies of reforming the system of subjects of administrative law of Ukraine. Logical-semantic method was used for formulation and in-depth study of the conceptual apparatus. The dialectical method of cognition made it possible to investigate the problems associated with the definition of the concept of "public administration". The application of methods of modeling, analysis, synthesis, generalization and analogy made it possible to formulate the conclusions of the study. Conclusions of the research correlate with the delineation of the institutional component of public administration in Ukraine. The authors have made qualitative and quantitative changes concerning the updating of the subjects of administrative law. At the same time, in the conditions of development of Ukraine as a democratic and rule-of-law state, all reform initiatives should be systematic and consistent with each other, therefore, during the study, the features that characterize the subject of public administration are highlighted. The scientific and analytical monitoring of the state of the introduced changes and the consequences of the implemented administrative reform measures for the classification of the subjects of public administration was carried out. Practical implications. The results of the research will help to understand the basic aspects of the content of public administration better and can be used in the research field in order to further study the issue of transformational changes that governing subjects under the background of actualization of trends of democratization and humanization of administrative processes.