This paper studies the evolution of urban form in both physical and social manifestations through an examination of the transformation of the Chinese capital from a planned imperial city into a modern metropolis in the early twentieth century. The newly created municipal government sought to modernize Beijing through public works to improve the old urban infrastructure. Consequently, city walls and gates were reconfigured; streets were paved, widened and expanded; and new rules of urban planning and zoning were introduced. Reflecting changes in political power relations, the modernist transformation in the urban built environment was evidently brought about by a combined force of Western influences and Chinese indigenous developments, especially by a shift in ideological allegiance from imperial authority to people's rights, by the state's increasing intervention in urban affairs, and by new technologies transmitted from the West.