The purpose of this study is to examine association between college students' background variables, degree of exercise participation and positive emotion among subjective well-being. Respondents of this study were college students in Taiwan. Data was collected through online questionnaires and 400 valid questionnaires were counted. Results of statistical analysis were 1) genders, grades, students in public/private school etc. won't affect college students' subjective well-being, 2) degree of exercise participation were found positively correlated with college students' positive emotion, 3) degree of exercise participation and college students' subjective well-being is positively related, 4) college students' subjective well-being will be affected by the degree of exercise participation through positive emotion, positive emotion was found as a mediator in this module.