Abstract: Using the data obtained from 322 college students, this paper discusses the relationship between significant others' support, subject-specific self-efficacy and college students' career adaptability. The results show that there is a significant positive correlation between significant others' support, subject-specific self-efficacy and college students' career adaptability. Among significant others' support, parent support, friend support, school teacher support, and enterprise mentor support, in addition to other support, are significantly positively correlated with college students' career adaptability. Moreover, significant others' support plays a notable role in the prediction of college students' career adaptability, while discipline-specific self-efficacy has a remarkable partial mediating effect in the relationship between significant others' support and college students' career adaptability.