This dissertation explores the dynamic interplay between entrepreneurship and economic change in socialist China (1958--1978) by retracing the persistence of private entrepreneurial activity and the Chinese Communist Party's enduring struggle to suppress it. Through the analyses of official archives, original datasets, interviews, and unconventional sources collected from Chinese flea markets, the dissertation shows how, within the interstitial spaces of society, there existed more dynamic realms of economic activity. Entrepreneurial actors, ranging from ration certificate traders to underground factory owners, circumvented formal institutions and established alternative channels for the flow of labor, goods, capital, and knowledge in the economy. Although these individuals were denigrated as ``speculators and profiteers" and, for three decades, made the subjects of intense political struggle, they served productive functions and filled critical voids in the economy. Over the course of the 1960s and 1970s, their activities became increasingly collusive, ubiquitous, and normalized in local society. When top-down market-oriented reforms were finally introduced in the late 1970s, they were, in many instances, a formalization of informal practices that were already pervasive. This dissertation thus challenges the still-dominant view that entrepreneurship disappeared during ``socialist transformation" and re-emerged only after Reform and Opening Up. It shows that throughout China's socialist era, bottom-up entrepreneurial forces continued to operate and reshape how the economy functioned in practice.