The purpose of this study is to explore the concept of youth's social participation competency and identify subconcept of the competency such as personal citizenship, community citizenship, global citizenship. The concept of youth's social participation competency has been described as many different words such as youth citizenship, civic participation, social engagement. This study, however, tries to understand it as social participation which is the fundamental activity of youth learning and defines its sub-constructs in three different levels considering youth psychological and behavioral development levels. Delphi method had been conducted to define its concept and sub-competencies, and twice surveys conducted to examine their validity and credibility. The results of the study is to find personal citizenship could consist of sense of rights, sense of responsibility and morality; community citizenship is composed of respecting diversity, political participation, and community service; and global citizenship is comprised of national identity, contributions for international society, and global communication. Moreover the confirmatory factor analysis show high model fit index in their measurement model.