This study aims to explore whether social stratification and financial capital have influences on educational tracking of senior high school students in Chiayi and to what extend these influences are after the implementation of the 12-year National Basic Education Policy in Taiwan. This study applied Questionnaire Survey method as research method and was conducted in July, 2016. 246 freshmen in public and private senior high school students in Chiayi were selected as sample in this study. Two measurements were taken to measure social stratification of the students: Parents' education level and parents' occupation. Two measurements were taken to measure financial capital of the students: Monthly household income and cost of after-school tutorial education. Four measurements were taken to measure educational tracking of the students: Top-ranking public high schools, ordinary public high schools, public vocational high schools, and private vocational high school. The results of this study were as following: 1. After the implementation of the 12- year National Basic Education Policy, social stratification and financial capital to some extent still have influences on educational tracking of senior high school students in Chiayi. 2. In terms of social stratification, students with parents' education level of bachelor and master degree, upper occupation class, and family's monthly household income above NTD 100,001 have higher possibility to study in top-ranking public high schools. 3. In terms of financial capital, the students with family's monthly household income above NTD 100,001 and financial support for after-school tutorial education have higher possibility to study in top-ranking public high schools. The students without financial support for after-school tutorial education have higher possibility to study in private vocational high schools. 4. Hierarchical regression analysis shows: In top-ranking public high schools, parents' education level and occupation have higher significance on students' educational tracking. In ordinary public high schools, monthly household income has higher significance on students' educational tracking. In public vocational high schools, social stratification and financial capital do not have significance on students' educational tracking. In private vocational high school, fathers' education level has higher significance on students' educational tracking.