The article analyses theoretical approaches to the phenomenon of social entrepreneurial activity related with different components of this business. In the course of research the relation of social entrepreneurial activity with whole entrepreneurship was revealed. Moreover the specific character of social entrepreneurial activity caused by entrepreneurs' regard to the social problems is considered. The article examines the processes of development of social entrepreneurial activity in modern Russia. Besides, the article analyses social entrepreneurial activity as a possible factor of regional development (by the example of the School of social entrepreneurial activity in the Irkutsk region).