Unlike anticorruption institutions elsewhere, China’s anticorruption practices follow a self-regulatory model: it is regulated by the very institution that is targeted by anticorruption. Compared with its role in judicial affairs, the Party’s involvement in anticorruption investigation is much more forefront, direct, and prominent. In this chapter, I track the origin and institutional evolution of the Party’s disciplinary system during 1927-2012. I point out that the Party’s institutional design is founded on the cardinal principle to preserve the unified (absolute) command of the Party Center. Thereby, how to reconcile between the imperative to uphold this principle and the need to provide a measure of autonomy for disciplinary institutions to avoid capture has been the main theme of the disciplinary institution-building process. The introduction of a tiered interlocking disciplinary decision-making structure, the segmented investigation process, and the “dual-leadership” model are the direct outcomes of the Party’s efforts to balance the conflicting needs mentioned above. These arrangements had fueled the rise of the CCDI but also brought several problems and challenges, including legal deficiency, jurisdictional frictions, resource shortage, incentive issues, and abuse, which had set the stage for Xi Jinping’s unprecedented anti-corruption campaign and disciplinary reform upon his taking power in 2012.