With the progress of urbanization and the expansion of urban size, cities are increasingly emerging as the center and subject of society. Urban agriculture, as a distinctive form of agriculture closely intertwined with urban development, is also garnering escalating attention from people. Owing to the blurring of the urban–rural divide and the continuous infiltration of urban elements into rural areas, a complete consensus has not been reached within the academic community regarding the spatial scope and form of urban agriculture, which poses a substantial impediment to the in-depth advancement of research and practice in urban agriculture. Based on collating the history of urban agriculture development and previous researches, this book puts forward the theory of four-dimensional development of urban agriculture, with the hope of facilitating the clarification of debates, consolidating consensus, deepening researches, and promoting development.