Since the creation of the stratumic Blau-Duncan status attainment model for the study of social mobility (Blau & Duncan, 1967: 131–140), some models have added six perspectives, including gender, race, peer group, political loyalty, unit status and network relationship (Yi Zhou, 2009: 206–225) and reformed it from different research levels such as individual, relation, organization, and society. However, sociologists’ empirical studies on the mobility of social status of the Chinese people emphasis on pre-endowed factors, such as effect of father’s educational attainment and occupational status on children’s social status mobility, self-motivated factor, the effect of one’s education level and first occupation on their current social status. In addition, some studies have also added some intermediary variables with Chinese characteristics (Yanjie Bian, 2002: 21–32) and other institutional factors, such as “CPC membership” (Walder & Hu, 2009: 1395–1427), “ownership form of work unit”, “household registration” and “family social relations” (Wenhong Zhang, 2006: 221–245). These studies mostly focus on exploring the causes and means for attaining occupational status, while few have examined the changes in occupational status. Therefore, this study intends to answer the following questions: is there any change in a person’s occupational status after he/she gets employed? Does his/her occupational status remains unchanged after he/she was first employed, or has he/she self-motivated upward or downward mobility?