My current research centers on three major themes: 1. comparative administrative law and its application; 2. constitutional authority and constitutional politics; 3. transitional justice in Taiwan and beyond. All are closely related to the exercise of public power. From the perspective of comparative administrative law, the legitimation of public power is context-dependent. While analyzing the divergence of national regulatory regimes and judicial doctrines, I have looked into the dynamics among law, politics and social changes in Taiwan, South Africa, Poland, and Japan. Meanwhile, I am particularly interested in the formation of constitutional authority and the debates over constituent power in East Asian countries. My concerns about transitional justice come from the cases of democratization and the restoration of liberal constitutionalism in South Korea and Taiwan. I have edited a book on the constitutionalization of transitional justice in the world. In the coming years, I would explore the topics regarding legitimacy of the administrative state, constitutional prelude to democratization in Taiwan, and rationality review in the modern regulatory regimes.