This study aims to examine the ever-changing constitutive meaning of the Taiwanese identity from a generational perspective. We argue that the idea of identifying-as-Taiwanese has been transformed from a primordial-based ethnic identity to a civic-based national identity, which can be systematically differentiated between younger and older generations. By using data from the 2013 Taiwan Social Change Survey (TSCS)-National Identity module, the results reveal that youth are more likely to identify themselves as Taiwanese because of their affiliation with the political community and their objection to reunifying with China, while the elderly tend to consider themselves to be Taiwanese based on ethnic ties and historical memories. The generational differences within the Taiwanese identity not only explain why this identity has become more acceptable in society, but also demonstrate the formation of a new Taiwanese nation.