Abstract: Intra-party supervision is the basic characteristic of Marxist political parties, the core means of the CPC′s party management and the important guarantee for realizing leadership and governance. Since its founding a century ago, the CPC′s intra-party supervision has gone through four stages: fruitful exploration during the new-democratic revolution, tortuous progress in the socialist revolution and construction, recovery and development in the era of reform and opening up, and a leap in the strategy of socialism with Chinese characteristics for the new era. A review of the CPC′s century-long exploration of intra-party supervision is of great value and enlightenment: intra-party supervision is a key link in party governance and self-governance and we must always give prominence to intra-party supervision; intra-party supervision is closely related to the strategic arrangement of the Party′s leadership and governance and must be closely related to the realization of the historical tasks undertaken by the Party; intra-party supervision is a long-term practice of Marxist political parties and, to maintain and strengthen intra-party supervision, we must pursue innovations and breakthroughs in daily and long-term supervision; intra-party supervision is, in essence, self-supervision, so we must have the consciousness to face up to problems and the courage to turn inward for self-criticism and transformation.