The purpose of this study was to determine how the degree of self-determination varies depending on the autonomy, competence, and relatedness of the basic-psychological needs, and to find the educational ways to improve self–determination. Longitudinal data of the KELS 2013 (Korean Education Longitudinal study 2013) was used in this study. Among the collected data, this study used several variables which were self-management, social self-concept, academic self-concept, relationships with teachers, relationships with friends, parental interaction, and external regulation motivation. Results showed that self-management, academic self-concept, relationships with teachers, and parental interaction have negative influences on external regulation motivation. In addition, the analyses of relationships between autonomy, competence, relatedness and self-determination showed that all statistically significant relations among variables, and autonomy had the highest correlation with self-determination. Based on these results we discuss the specific ways that can foster the needs for autonomy, competence, and relatedness to enhance self-determination.