Paying specific attention to influences of life events and different timing of taking compulsory military service for Taiwanese people, this dissertation explores time-dependence of job mobility and class mobility throughout careers. The author criticizes that previous research of social mobility focusing on either differences between father’s and son’s classes or the relationship between one’s initial and current statuses do not realize the process of status attainment in which individual characteristics and life courses continuously interact with external structures in the labor market. The analyses in this dissertation demonstrate the dynamics of career mobility by specifying two career stages and investigating the differences in paces and mechanisms of job change and class mobility. All findings lead to the conclusion that the time dependence of career mobility is deeply embedded in the context of life course in a society. For Taiwanese men, the timing of taking CMS (i.e., before or after their first entry into the labor force), which is strongly correlated with their educational level, is crucial to the pace and type of career development. For Taiwanese women, their trajectories of mobility follow the typical scenario of career mobility in which job change happens often during the early career and then settles into relatively stable employment in the later stage. Compared to job mobility, status attainment is more stable and consistent throughout the life time. After specifying the directions of job mobility, results show that upward and downward mobility, which bring significant change in occupational prestige, do not show gender differences in their transition rates, and their patterns are consistent throughout careers. With respect to the transition between social classes, moving into ownership (including employers and self-employed) in later careers is a mainstream transition for all Taiwanese people in spite the fact that women have much lower transition rates than do men. Moreover, this dissertation also examines inter-sector and intra-sector mobility in segmented labor market in Taiwan. Taking selection bias into consideration, this research found that under the assumption of homogeneity, the treatment effects of initial attainment in the public sector have negative effects on job mobility throughout careers. However, when heterogeneity of treatment effects are taken into account, findings reveal that there is no significant heterogeneity in this treatment effect for Taiwanese men, but for Taiwan women, the more likely they are to attain a position in the public sector at the time of first entry into the labor market, based on their educational achievement and social background, the more they benefit via low transition rates of job mobility in their work lives. / text