Since the founding of New China, the Communist Party of China has continued to promote the process of national system construction, which is the process of continuous system innovation under the guidance of the basic principles of Marxism.This historical process is divided into three phases:the initial exploration of establishing and perfecting the socialist system (New China's founding-the 3rd Plenary Session of the 11th CPC Central Committee), the creation and establishment of the socialist system with Chinese characteristics (the Third Session of the 11th CPC Central Committee-the 18th National Congress of the CPC), the maturity of the socialist system with Chinese characteristics (since the 18th National Congress of the CPC).This is a one-way, consistent and advancing process, and in essence, it is the theoretical and practical exploration of the Party leading the people to the socialist system.From the establishment of the socialist system to the establishment of the socialist system with Chinese characteristics, it is a historical leap in the history of the socialist system, and the establishment of the socialist system with Chinese characteristics to the maturity of the socialist system with Chinese characteristics will be another new leap in the history of system construction.The 4th Plenary Session of the 19th Central Committee of the Communist Party of China made pioneering research and systematic solutions to the problems of the national system and the national governance system, comprehensively summarized the significant advantages of the socialist system with Chinese characteristics and the system of national governance, scientifically depicted the "map" of the socialist system with Chinese characteristics, and systematically innovated the theory of the socialist system with Chinese characteristics.It marks that the Party's understanding and practice of national system construction have reached a new height.