A legislature in an authoritarian system is usually portrayed as a rubber stamp. That is, the legislature only has symbolic meaning and no substantive functions. If an authoritarian regime has been undergoing democratic change, however, its legislature must have also been transforming from one that is very weak (a rubber stamp) to one quite strong (a roaring lion). How does such a transformation take place? This phenomenon is the main focus of this paper. Using the case of Taiwan, this paper manifests the relationship between legislatures and democratization from a dialectical perspective in which a legislature can neither alone promote democratization in a given system, nor arise as a strong legislature solely as an effect of democratization. The changing relationship between legislatures and the political systems they establish should on the one hand be cumulative. That is, the systems must have been constantly undergoing some democratically oriented changes with their legislatures, thus correspondingly reflecting those changes. On the other hand, the changing relationship between the two should result from both institutional influence and individual initiative. That is, the institutional arrangements of a given system should establish the foundation for its legislatures being able to realize democracy. However, if individual efforts both from inside and outside of the legislatures are not focused on pursuing democracy, the institutional mechanisms cannot be fully utilized to fulfill their given functions. With the foregoing theoretical propositions, in the case study of Taiwans Legislative Yuan, this paper further investigates the Legislative Yuans change and how it has been linked to Taiwans democratic development.