Based on the complex analysis of the peculiarities and potential of the formed approaches to understanding of regional innovation sub-systems (RIS), the author has proposed his definition of RIS, new interpretation of their functions and structure. This approach lays emphasis on minimization of the transaction expenses and administrative barriers in the activities and interaction of RIS subjects, improvement of the efficiency of regulatory institutions, creation of the incentives for the communication and cooperation of various structures and stake-holders. The results of the present research can be used for improving the regulatory policy and the system of the strategic development of Russian regions’ innovative development.