In Taiwan, the election timing of Presidential election and Legislative election were changed to concurrent from 2012. Concurrent elections change the interactions of the Presidential candidate, the Legislative candidates and the party, and the intra-party relation. This study took the Democratic Progressive Party (DPP) for example, and attended data through in-depth interviews and documents analysis. This study intends to find the changes of the DPP in organization and behavior, and describe the interactions of the Presidential candidate, the Legislative candidates and the party in campaign. The major findings of this study are describe as follows: First, change of election timing made the power more centralized in the President or the Presidential candidate in the DPP, resulting the party became more presidentialized. Second, the political competition in local politics tended to nationalized, made the party system nationalized. Third, the fictions in the DPP weakened the power of the President or the Presidential candidate, reducing presidentialization of the DPP. Last, Concurrent elections were beneficial to intra-party integration, reducing the competition in local politics.