Adults' career choice is not an abrupt event, but an outcome of continuous development throughout childhood and adolescence. In the developmental process of one's career, personal characteristics and contextual resources come into play. The goal of the present study is to examine how family socioeconomic status, adolescents' vocational aspirations, and high school contexts affect their occupational attainment in young adulthood, using two cohorts of data from the Korean Education and Employment Panel. Cohort 1 consisted of 1535 individuals (49.3% female), and cohort 2 consisted of 1473 individuals (53.5% female). Both cohorts were surveyed during their senior year of high school (Time 1; Mage = 17.8) and followed up until young adulthood (Time 2; Mage = 25.8). The results reveal that having high vocational aspirations and attending academic high school predict attaining higher-status occupations for both cohorts. Family background has positive direct and indirect effects on occupational attainment for cohort 2, while it only has an indirect effect on occupational attainment via types of high school for cohort 1. Implications in the context of constructing social systems to support adolescents' career development are discussed.