This is an empirical study of a migrant workers' church in the context of China's urbanization. The researcher adopts the case study as the primary research method. Based on indepth interviews and participant observation at the " Mount of Olives Church" in City A, the study explores the relationship between urbanization and migrant worker churches by describing the rise, growth and transformation of this congregation. Previous research on migrant worker churches has mostly been conducted via an anthropological approach, taking individual Christians as the unit of analysis, to explain the meaning of faith to migrant worker Christians. While this study still focuses on migrant worker Christians, it approaches them from a sociological perspective, taking church organization as the unit of analysis. The study finds a bilateral interaction between urbanization and church transformation : on the one hand, urbanization leads to the rise of migrant worker churches and shapes the churches in terms of resources, institutionalization and culture; on the other, church leaders have actively pushed for reforms and adapted churches to urban life.