The purpose of this paper is to clarify how the curriculum of "Sogo Gakka" senior high school affects the course choice of students. Students who are undecided about their careers enter "Sogo Gakka" senior high school and experience various learning courses in their first year. In their first year, they choose subjects according to their career expectations, but do subject choices ultimately have any influence on students' course choices? Based on the result of a panel study in a certain "Sogo Gakka" senior high school, I clarify, from the viewpoint of curriculum tracking, the process of career choice changes among students. After the 1990s, there was an increase in "new types of high schools" which included a unit system and "Sogo Gakka." The biggest characteristic of these "new types of high schools" is that students can choose classes depending on their interests. "Sogo Gakka," which started in 1994, in particular changed the frame of postwar high school education of the double feature, which includes an academic course and vocational course. In "Sogo Gakka," which is "the new third course", students can learn both academic subjects and vocational subjects. In this paper, I pay attention to the causes of change in expectation from getting a job to entering a university after high school. As a result of this analysis, I found that domestic study time and high school grades had no effect on the change in the expectation. In addition, course credits of vocational subjects had no effect on the change, too. It becomes clear that course credits of mathematics influence the change. Based upon the foregoing, it is suggested that the amount of credits of mathematics affects the course change in expectation from getting a job to entering a university. In addition, there was a statistically meaningful effect on the change. I used logistic regression analysis with individual subject grades, gender, domestic study time, and curriculum as the main independent variables to study the overall effect of these factors on the individual's course change. In addition to this, I analyzed these effects from a time-varying perspective. The result showed that the students who took many credits of vocational subjects were more unlikely to change the course in the first half of school life. This shows that curriculum tracking affects students' course choices soon after entering "Sogo Gakka" senior high school. This empirically based study reveals that subject choices in the students' first year decide their final course choice.