Abstract: Urban spatial expansion is the most important manifestation of urbanization process, and urban land– use change is the most direct indicator of urban spatial extension, namely, "spatial urbanization". Along with global urbanization, urban spatial expansion has become a hot field in the research of urban development. Foreign research on urban spatial expansion started to unfold when Quantitative Geography Revolution took place in the 1960s, whereas in China it had a relatively late start in the 1980s. Now China is undergoing rapid urbanization, problems and conflicts in urban space expansion are becoming increasingly prominent. Since 2000, a large number of achievements have been made in this field, and need to be sorted out. Based on the progress of theoretical studies and the change of the content of urban spatial expansion research, this article uses the methods of literature search and comparative analysis to review the research progress. The urban spatial expansion researches are reviewed from five aspects, including expansion types, expansion patterns, dynamic mechanism, simulation and prediction, effects and regulations. Through discussing the different research contents, research methods and research conclusions, and combining classification and comprehensive review of foreign and domestic researches, this review discusses the characteristics and inadequacy of the current research, and suggests future research directions. The trend of urban spatial expansion research in China are summarized in four aspects as follows: (1) future research will become more and more focused on urban spatial simulation and prediction; (2) the research on spatial expansion pattern at the regional scale and in the less developed central and west areas will be strengthened; (3) by taking research experience and methods from other disciplines for reference, we should strengthen the fusion of multidisciplinary methods to be better able to solve the problem of urban spatial expansion; (4) based on the status and environment of urban development research in China, the theory and method of the research need to be innovated, in order to narrow the gap between domestic and international research levels. This review provides a reference for further studies of urban spatial expansion as well as the guidance for a healthy, sound and coordinated development of urban space.

Key words: prospect, research review, spatial expansion, urban