Remaining committed to self-reform is one of the ten valuable historical experiences gained over the past century through the effort of the Party, and it is the Party’s distinct character, greatest advantage and remarkable sign. The Communist Party of China has gained the strong core of leadership by constantly undertaking self-reform, correcting mistakes, purifying the team, and tempering the style of work. The great new project of Party building is the practical basis of self-reform, and the “three styles of working” are important experience and theoretical innovation of Party building. Rigorous self-governance is the due meaning of Party building. Under the conditions of ruling and market economy, it should be implemented in all activities of Party building. The full and rigorous self-governance in the new era creates a new realm of self-reform of the great Party in 100 years, and reflects the deep grasp of the governance law. Enhancing the ability of “four selves” is the key to self-reform in the new era.