The "primary stage of socialism" (sometimes referred to as the "preliminary stage of socialism" ), introduced into official discourse by Mao Zedong as the "initial stage of socialism", is a sub-theory of Chinese Marxist thought which explains why capitalist techniques are used in the Chinese economy.
The concept of a primary stage of socialism was conceived before China introduced economic reforms. When discussing the necessity of commodity relations at the 1st Zhengzhou Conference held between 2 and 10 November 1958, Mao Zedong—the Chairman of the Communist Party of China's Central Committee—said that China was in the "initial stage of socialism". Mao did not elaborate on the idea; his successors did.
Xue Muqiao introduced the term "underdeveloped socialism" in his book China's Socialist Economy. The book was written in the orthodox Marxist–Leninist framework enunciated by Joseph Stalin in Economic Problems of Socialism in the U.S.S.R. (1952). Xue wrote that within the socialist mode of production there were several phases and for China to reach an advanced form of socialism it had to focus on developing the productive forces. He proposed a theory in which the basic laws of economic growth were those in which "the relations of production must conform to the level of the productive forces". Similarly to Stalin, Xue considered the productive forces to be primary and that this was a fundamental universal law of economics. Unlike Stalin, Xue believed there were principles that guided the socialist transition, the key one being the principle of "from each according to his ability, to each according to his work"; this principle would guide socialist development, even when China had reached advanced socialism, and would be replaced with "from each according to his ability, to each according to his need" only when there existed general abundance. Xue based his arguments upon the economic policies pursued during the Cultural Revolution, which he believed had led to "the most severe setbacks and heaviest losses suffered by the Party, the state and the people since the founding of the People's Republic".