This article intends to study the trajectory of modification of DPP’s “Regulations on the nomination of public officials candidates” since 1989. In addition, the authors will track down the establishment of DPP’s “Regulations governing the nomination of presidential and vice-presidential candidates in the year of 2000”. In order to help authors observe these subjects, a framework integrating system model and the new institutionalism is suggested in this article. The article is divided into four sections. The authors will first suggest a broad analytical framework, which helps us observing and explaining the change or creation of nomination institutions in political parties. Second, the formulation and adjustment of DPP’s “Regulations on the nomination of public officials candidates” will be discussed. Third, we will explore why the DPP’s “Regulations governing the nomination of presidential and vice-presidential candidates in the year of 2000” was established and its subsequent impacts. Conclusion is the last part. Major findings are: 1) the path of the change of the DPP’s nomination institution is consistent with our arguments. New rules are created primarily in response to new needs inside the party, but the actual path and operation are shaped by the interests holders of the old rules. 2) Those who advocate new rules enthusiastically may be explained by the fact that they foresee the expected payoffs from taking shape the new rules. It is especially true if we explore the origin of the “Regulations governing the nomination of presidential and vice-presidential candidates in the year of 2000.” 3) The incremental changes of weight of the opinion polls in DPP’s party primary also support the argument that once a new rule is set, it will limit the course of actions that actors may choose. 4) The authors also made some predictions on what would happen to the DPP’s “Regulations on the nomination of public officials candidates.”