Purpose: The purposes of this study were to explore to what extend the social support would affect on the high school students of the department of physical education for their career development in Taiwan. This research further focused on the mediator effect of students' career beliefs on their career development. Methods: The data collection utilized the random sampling with cluster adopted from high school students of the department of physical education in Taiwan, with 679 usable subjects. The quantitative analysis of the questionnaires was conducted by descriptive statistics, correlations analysis, and structural equation modeling. Results: The findings showed that the social support for students had positively impacted on their career development. Furthermore, their career beliefs had the mediator effect on the social support and their career development. Conclusions: The more the students got the social support, the more their career would be promoted. In particular, if the students had got more career beliefs, it was helpful to their career development as well.