In Hong Kong, which transitioned from a colonial to post-colonial One Country-Two Systems structure, sustainability implementation rests on two institutional pillars: education, which drives the city's knowledge-based economy, and family system. In light of the recent policy demands to strengthen higher education and family systems by capitalizing on the unique advantages of the post-colonial era, the purpose of this study was to: (1) describe and analyze sustainability values of the first-year university students; and (2) investigate roles of family and educational systems in the process of their formation. The mix-method study stressed the importance of discerning and analyzing sustainability value formation in order to create in-depth understanding of the curricular adjustments that align the sustainability mindset of Hong Kong students in the context of the One Country-Two Systems under the pressing demands of global economy. The study relied on the use of two systems theoretical frameworks employed within sustainability education (Sterling, 2003) and family (Bowen, 1957/1974) fields. Data sources included questionnaires of 4985 Hong Kong first-year university students; and 31 semi-structured interviews of Liberal Studies teachers. The quantitative findings showed that 85% of the students believed that their family influenced their environmental values; reported a significant negative coefficient (-0.044) between the two student cohorts in relation to family influence; and showed that family influence on students' sustainability values differed by gender. The qualitative results revealed the overarching themes of Family Income, Role Modeling, and Shared Responsibility as three major descriptors of family influences on sustainability values of Hong Kong students.