Higher business education has become a crucial driver of change in achieving sustainable development because it can educate future leaders who champion environmental sustainability initiatives in the corporate world. Given that there is a gap between sustainability knowledge taught in school and what it practiced at the workplace, this study aims to assess in-school students (undergraduate seniors) and already graduate students (alumni)’s perception toward environmental sustainability that provides an exploratory lens to advance youngster’s pro-environmental attitudes and practices. By administrating a survey questionnaire under the theory of planned behavior (TPB) model, 142 in-school students and 166 alumni from a China’s university participated in a survey questionnaire. Overall results show that students ranked external referent groups (subjective norm) as the most important factor, followed by the personal beliefs (attitude) and perceived competence of engaging in the behavior (perceived behavioral control). Compared with the alumni, the in-school students have a more favorable perception of environmental sustainability. Though, the biggest perception gap between in-school students and alumni was observed in the subjective norm section where in-school students more often agreed to the importance of university administrators and professors as valid referent group in promoting greener issues. The study findings offer practical recommendations to educators and corporate leaders for further facilitating environmental sustainability.