The transitional period refers to the period from the founding of New China in 1949 to the completion of socialist transformation in 1956, and the transition from a new democratic society to a socialist society. The main contents of the Party's general line in the transitional period are summarized as "one modernization and three reforms", in which "one modernization" refers to socialist industrialization and "three reforms" refers to the socialist transformation of individual agriculture, handicrafts and capitalist industry and commerce.

As early as the eve of national liberation, the Second Plenary Session of the Seventh Central Committee raised the issue of the transition from new democracy to socialism. By the end of 1952, the task of national economic recovery was basically completed. According to Mao Zedong's suggestion, the CPC Central Committee, proceeding from the actual situation in China, put forward the party's general line in the transitional period as a guide for all work in the transitional period.

On September 25th, 1953, People's Daily published a slogan to celebrate the fourth anniversary of the National Day, officially announcing this general line, that is, "it is a transitional period from the founding of People's Republic of China (PRC) to the basic completion of socialist transformation.