The paper presents social participation of children – understanding of the idea and the character of the scientific discourse on it in the context of perceiving children as socially discriminated in their access to social and civic rights and activities, particularly the right to participate in social decisions. On the basis of analysis of social exclusion of children in the past centuries the Autor presents the change in social and citizen status of children that has been taking place in democratic societies. The Autor indicates on the crucial meaning of the Convention on the rights of the child and other documents in building this change and in explaining contemporary meaning of the idea and of the range and the level of possible participation of children. In the paper the very deep understanding of the idea of children’s participation based on the analysis of theoretical concepts is also explained. The Autor presents the dynamics and evolution of the theoretical background of the discourse on children’s participation and indicates on process of change: from theories of a child as a social actor and a child as able to act in social affairs, that dominated in last decades towards theories of liberal democracy, theories of inequalities, citizen’s participation, political theories, theories of governance and the theory of recognition as current theories that are used in this discourse. Finally, the development of today’s discourse on children’s participation and the promotion of its implementation in social practice are seen as crucial factors in elimination and counteracting social exclusion of children.