The purpose of this study was to examine how the career maturity of high school students was affected directly or indirectly by psychological separation from their mothers and through the mediation of self-concept. The subjects in this study were 496 juniors from regular high school in the city of Daegu, who included 243 boys and 253 girls. The measurements of this study were a career-maturity inventory, psychological separation inventory (PSI), and self-concept scale. The major findings of this study were as follows: First, career maturity had significantly positive correlation to conflictual independence from mothers for them. Second, as for the influence of psychological separation, and self-concept on career maturity, three variables, including competence self-concept, home self-concept, attitudinal independence from mothers, classroom self-concept, had significantly explanation of career maturity. Third, as a result of making a path analysis of the impact of psychological separation from mothers on career maturity through the medium of self-concept, conflictual independence gave a direct impact only, and its indirect effect was insignificant. The attitudinal independence showed both direct and indirect influences, for mothers had a significantly indirect impact only.