Taiwan's 2000 presidential election saw the first change in ruling parties. Although the Democratic Progressive Party (DPP) took the presidency once again in the 2004 presidential election, it nevertheless only gained a minority of seats in the Legislative Yuan. Owing to the fact that the opposition parties kept their hold on the legislative majority, the DPP failed in its attempts to reorganize the government, and nearly all of their numerous bills, policies, and personnel nominations were vetoed by the opposition parties. Through the application of the theory of divided government and focusing on the idea of obstructionism, this paper compares the periods of unified government and divided government regarding the actions of the Legislative Yuan and their various types of impact. Moreover, the research analysis contrasts with similar research from American academic circles, and in fact it finds that the legislative impact in our central divided government leans closer toward the main arguments given by the Sundquist school of thought.