This dissertation investigates why in the early 1950s the Chinese Communist Party launched the agricultural cooperative movement, a movement that in many crucial ways resembled earlier collectivization in the Soviet Union. Past research has treated China?s cooperative movement as a campaign imposed from above by Mao Zedong. By refocusing scholarly attention from the center to the localities, this dissertation discovers that in its early stage this movement had a measure of strong social support from below. Not denying Mao?s dominant role, this dissertation examines the roles of others who were not at the top of the party?s hierarchy. It shows how certain cadres at the provincial and prefectural levels first provided Mao Zedong with inspiration, evidence, and even theories, and finally succeeded in convincing him to endorse their plans. Refuting the conventional wisdom that takes this movement as a pre-determined one, this dissertation contends that it was the outcome of a complex combination of ideology, circumstances, domestic politics, and personal ambitions. In addition to highlighting institutional uncertainty and fluidity, this dissertation also studies the complex interplay between the state?s central planning and peasants as agents. Peasants were not simply the receptacle of policies formulated at the highest levels of power: they were always seeking to adapt to local conditions the directives that higher authorities sent down. By studying the cooperative movement at a key experimental site - - Changzhi prefecture in Shanxi province from 1950 to 1953, this dissertation explores the process of mass mobilization in the province and villages.