Abstract: In Lenin's What Is To Be Done?, the conception of ideological party building in the history of Marxist development and the history of proletarian political party construction has a pivotal position. Lenin put forward a series of concrete ideas on the theory, significance and method of ideological party building through deep exposition on the wrong ways of opportunists and revisionists in the Russian Social-Democratic Workers' Party, and expounded the significance of stressing scientific revolutionary theory, strengthening the indoctrination of revolutionary theory, establishing a nation-wide political newspaper and cultivating professional revolutionaries for the ideological building of the proletariat, which effectively promoted the development of the communist movement at his time and further enriched and developed the Marxist theory of party building. The enlightenment of Lenin's What Is To Be Done? for the ideological construction of the contemporary Chinese Communist Party is that we must adhere to the dialectical unity of Marxists ideas and CCP principles by firmly grasping the ideological leadership, adhere to the unity of practical efforts and strict party discipline by sticking to socialist faith and mission, and promote the study and education of party history with "online" and "offline" joint efforts.

Key words: Lenin, What Is To Be Done?, ideological party building, construction of political party, ideology