Although 35 years have passed since the democratic transition, there are several institutional and non-institutional factors demonstrating that Korean democracy has not sufficiently matured or consolidated. Among others, it is noteworthy to pay special attention to the problematic party politics and its formation process combined with the imperial presidential system.
 Against the background of premodern political culture endowing the president with a prerogative power, Korean political leaders tend to take authoritarian charismatic leadership as their political style, instead of rationally institutionalized leadership. The presidents and political leaders have shown authoritarian populist leadership during the authoritarian regime, and delegative populist leadership in the post-democratization era. They dominated state affairs and party politics, forming a monopolistic and factional party system.
 This article focuses on the problem of party politics featuring pre-modern party system and populist leadership clung to the old customs of personalized and factional politics in Korea, by emphasizing that both have been supported and strengthened through the party regulation since 1945. The finding is that in the Korean presidential system, party regulation and populist leadership have mutually influenced and are closely intertwined, resulting in malfunctioning party politics and democracy.