The essence, content, features and directions of implementation of public administration reforms in the conditions of decentralization are substantiated, on this basis, the regulation and structure, organizational-legal, administrative and institutional bases of branch reforming under the influence of internal and external factors, social factors, modern challenges management are proved. The methodological bases and practical aspects of development and implementation of changes in public administration in the context of the sectoral approach are determined. It is proved that in formulating proposals for institutional change in Ukraine an important task is to determine the strategy, tactics and specific measures for the full application of the Constitution of Ukraine and the basic laws governing the institutional development of management subsystems. It is emphasized that the current reform of public administration also includes sectoral components - education, health care, social policy in general, economic components, etc.
The basis of institutional change is the sectoral direction of modern public administration, improvement of legislation, dissemination of public positive perception of such changes and the formation of public and personal needs for change. It is established that the efficiency of Ukraine's reforms in the sectoral dimension, in addition to the presence of a political program, requires legal support, the formation of an effective system of state bodies to implement such changes, ensuring coordination of government efforts on sectoral reforms. New theoretical and methodological approaches to practical tasks in the field of institutional support of reforms are substantiated. It has been established that the reform of public administration should implement the tasks of state building based on the values of the constitutional system in the process of amending the Constitution of Ukraine aimed at improving the organization of state power subordinate to the goals of public life.
It is substantiated that in the socio-political plan the public administration reforms are conditioned by the need to resolve or minimize the contradictions of institutional interaction, which are formalized by the principles of governance. It is established that public administration reforms should implement the tasks of state-building based on value principles, aimed at improving the organization of state power, subordinated to the goals of social development. The methodological foundations and practical aspects of the development and implementation of changes in public administration in the context of the sectoral approach have been determined. It is proved that when formulating proposals for institutional changes in Ukraine, the necessary task is to determine the strategy, tactics and specific measures for the full implementation of the Constitution of Ukraine and the basic laws governing the institutional development of the management subsystem based on the sectoral approach.
According to the author's research, the peculiarities of the formation and development of government in 1991-2020 are identified and characterized: the stages of formation of the system of state power in Ukraine concerning public administration reforms (twelve stages); stages of implementation of public administration reforms (seven stages); stages of sectoral reform. Based on conceptual approaches to solving the problem of determining the scientific categories «reform» and «public administration reforms», «sectoral reforms» it is proposed to define the concept of implementation of public administration reforms as a set of institutional, organizational, legal and administrative means, forms and methods of management. The system approach allows to change the usual regulation of the behaviour of objects and subjects of management on the regulatory influence of the subject of management on public relations. It is established that the main problem of implementation of sectoral reforms is the inconsistency of organizational and legal support of the reform, the subjective discreteness of the reform and the asymmetry of the institutional context of reforms under decentralization.
