This paper studies the impact of Hong Kong's extradition bill amendment on Taiwanese youth's preference on the issue of Taiwan independence, which is the most important issue in cross-strait relations. In this study, students from National Chengchi University were selected as the sample by in-depth interviews. It was found that when respondents obtained news reports related to the Hong Kong's extradition bill amendment, they formed different stereotypes about the incident and influenced the preference on the issue of Taiwan independence. However, a more long-term study is still needed on Taiwanese youth's preference on the issue of Taiwan independence.