This paper aims to show that Taiwanese born in the 1980s constitute a “post-reform” generation whose perception of cultural difference and ethnicity may challenge the efficiency of the “four major ethnic groups” categorization as an analytical framework for research on Taiwanese youth's identity, political behaviour and social interactions. Using quantitative data from a questionnaire distributed in 15 universities nationwide in 2010 and qualitative data from interviews, this paper first focuses on the attitudes of Taiwanese born in the 1980s toward what are generally considered the three core elements of ethnic group-making in a Chinese socio-cultural context: patrilineality, locality and language. Then it shows that the combined effects of democratization, Taiwanization and contacts with mainland China have decisively impregnated their life experiences and influenced their perceptions of cultural difference. Consequently, the different aspects/ factors that contributed to the formation and the deepening of ethnic boundaries and ethnic conflict up until the 1990s are not effective anymore, nor are they significant for Taiwanese in their twenties. This process is transforming ethnicity rather than erasing it. Thus “having an ethnic identity” is still considered important by a majority, but its meaning and salience have changed, leading to the necessity to redefine, a process that could be undertaken using the concept of “symbolic ethnicity”.