Urban planning is a means for artificially differentiating urban space. It also shapes social interaction on the whole. While urban planning is fundamentally related to communications, it has been barely discussed in the communication field. Hence, I explain the impact of urban planning on social life and describe the intellectual trajectories of urban sociology and urban communication in order to draw more attention from communication scholars to urban issues. Then, based on the review of the spatial impact on social interaction, a conceptual framework is suggested—spatial media, which is defined as abstracted forms of objects exchanged in spatially differentiated social interactions. This conceptualization intends to overcome the limited understanding of the spatial impact on social life from different approaches to the physical impact on human behavior. The framework will direct the focus of the investigation of spatial differentiation toward the three significant social mechanisms of media: Social integration, social stratification, and civic participation. With the implication of spatial media, communication researchers are expected to contribute to the urban planning process by bringing communication factors to planning discussions.