Abstract: Understanding and exploring the regional differences in urban land use efficiency and their formation mechanism in the Yangtze River Economic Belt is of great practical significance for guiding the efficient utilization of urban land and achieving coordinated regional development. Based on super-efficient DEA model, gravity center model, Theil index and geographical detector model, this study systematically investigated the temporal and spatial evolution pattern, as well as regional differences and their formation mechanism of land use efficiency of 105 cities in the Yangtze River Economic Belt during the period from 2004 to 2014. The results show that the land use efficiency in the Yangtze River Economic Belt increased significantly in this period. Its geographical center of gravity generally shifted from west to east and from south to north. Spatially, there appeared "center-periphery" spatial differentiation patterns in the eastern, middle and western regions of the Yangtze River Economic Belt. The Theil index of urban land use efficiency in the Yangtze River Economic Belt indicates that there were significant differences among regions. Besides, the convergence of clubs emerged in its eastern, central and western regions, which was characterized by "convergence within the group and divergence between groups". In fact, urban land use efficiency is controlled by a variety of complex factors. From the overall perspective of the Yangtze River Economic Belt, the social economic factors are the most decisive factors for the spatial distribution and use efficiency of urban land. There are significant differences in dominant factors for different regions. From eastern region to central region and to western region, the dominant factors take on a characteristic of transforming from regional conditions and internal forces to external factors.
Key words：urban land use efficiency ; regional difference ; formation mechanism ; Yangtze River Economic Belt