The article identifies and clarifies the normative, substantive and procedural foundations of the innovative school networks (ISN) of Ukraine. To achieve this goal, a set of interrelated methods has been used: general scientific: analysis, synthesis, abstraction, comparison and generalization, which have enabled to study official documents of educational reforms; specifically scientific: structural-logical analysis has made it possible to determine the normative principles of the phenomenon; system-structural and system-functional analysis have become the basis for revealing of the content and procedural principles of activity of innovative school networks of Ukraine. The main provisions of the activities of innovative school networks are defined: the need to diversify the education system through the creation of a network of innovative schools; development of an appropriate legislative framework for regulating the activities of joint educational institutions; government stimulation of change, the opening of new schools and the establishment of partnership relations between schools. The substantial foundations are clarified: the readiness of the school to provide quality education to all students and to cooperate in the dissemination of progressive pedagogical and managerial experience; professional development of teachers and school administration; implementation of active measures to enhance cooperation with students’ parents, local educational administration, the public; the introduction of an integrative-activity approach to the teaching of the disciplines of the natural-mathematical cycle. The organizational forms of the activity of the ISN of Ukraine are characterized: 1) the teacher’s mutual attendance of training sessions and a joint analysis of their results; 2) scientific-methodical and practical conferences; 3) dissemination and popularization of the acquired knowledge and information through printed materials, video, the Internet; 4) conducting comprehensive monitoring of the effective implementation of innovative pedagogical technologies in the work of general educational institutions. The study does not exhaust all aspects of the above problem. The content and procedural principles of the activity of innovative school networks of Ukraine, in particular, «Step by Step», «Environment» and «Azimuth» projects deserve further study.