Substantial attention has been focused on the phenomenon of landscape fragmentation in urban environment that stems from rapid urbanization and social-economic developments.Intensification of landscape fragmentation is increasingly considered as an essential ecological indicator that strongly influences the processes,functions,and services of urban ecosystems.Hence,in this study,on the basis of the interpreted land use map from high resolution SPOT XS imagery,we utilized a series of moving-window analysis and gradient analysis combined with selected landscape metrics to investigate the spatial distribution and local differences of landscape fragmentation;and further examined its relations with urbanization and social and economic developments in Beijing urban region,China.The result shows that,at the patch level,urban built-up lands occupied 63% of the entire study area and were well-connected,and less-fragmented.Whereas urban green lands constituted 33% of the area,with the characteristics of uneven distribution,and relatively high fragmentation status.At the landscape level,we found that landscape fragmentation,indicated by metrics of patch density(PD),edge density(ED) and landscape division index(DIVISION),was considerably higher in urbanizing fringes than urban central and rural areas.In the eight directions along the urban-to-rural gradient from the urban center outward,the degree of landscape fragmentation rose initially and fell down afterward,displaying a single peak pattern in urban fringes.Regression analyses indicate that the relationship between the degree of landscape fragmentation and the level of urbanization is significant in form of binomial equation and emerging as inverted "U" pattern in the diagram,exhibiting a threshold for the increase of landscape fragmentation when the degree of urbanization approached 42%—45%.Identification of this threshold suggested that urbanization could pose both positive and negative effects on landscape fragmentation;that is below the threshold,urbanization has positive effects whereas above the value,it imposes negative effects on landscape fragmentation.Further investigations revealed that the social factors of population density and the number of household were the primary direct drivers of landscape fragmentation;while rapid economic development,which accelerates urbanization,has imposed indirect impacts on the intensification of landscape fragmentation.This study developed a framework for analyzing and enhancing our understanding of the nature of landscape fragmentation.Our derived results not only could be used as an important tool for assessing the spatial pattern of urban ecosystem,but also provided scientific basis for effective landscape planning and design of sustainable urban environment.