Availability of appropriate institutional infrastructure is the prerequisite for the dissemination of social innovations for sustainable (balanced) development of the region. It should be considered from the viewpoint of the interrelated work of all participants of the innovation process in the region (local governments, scientific and educational and research institutions, business sector, institutions supporting innovative activity), provided the introduction of socially oriented programs, projects, platforms, startups, the public benefit of which will be manifested at the regional, national, and international levels. The insufficient regulation of some issues of the development of innovation infrastructure and the low level of financing of all elements of innovation infrastructure leads to some unsystematic and inconsistent development, especially at the regional level, which is confirmed by significant interregional imbalance in the placement of institutional infrastructure of innovation activity. Priorities of the development of social innovations through the prism of the institutional infrastructure of innovation activity at the regional level are established. The proposed structural and logical construction of assistance to the formation of institutional infrastructure to support social innovation in the region on the downward principle is built on balanced development of the ecological, social and economic components of the region. The authors note that the generation, production and dissemination of social innovations in the regions may be intensified through the creation of science-education and research centers with appropriate state support, as well as the introduction of regional instruments for preferential lending to socially-oriented enterprises, technology parks, technopolises, innovative business incubators and business -accelerators