城乡建设用地是土地利用的重要组成部分，是人为活动对自然改变最深刻的方面。我国工业化、城镇化发展迅猛，大量农用地转化为非农建设用地，在这一过程中，城乡非农建设用地分散分布现象异常突出。城乡用地分散分布会使基础设施建设成本增加、加大环境保护的难度、加重资源约束，因此研究用地分散分布及其机理对我国实现绿色可持续增长具有非常重要的意义。然而，目前大部分土地利用的相关研究关注城乡土地利用的转化及其影响因素，较少针对性的刻画城乡建设用地的分散情况及其机理。 本文以GIS为技术手段，从时间和空间的角度利用定性和定量相结合的方法分析了全国从1990-2010年城乡建设用地的分散分布及其变化，结果显示：（1）1990-2010年，我国城乡建设用地分散度呈增加态势，增加了11.34%。分散度扩张速度从1990-2000的4%加速到2000-2010的7%；（2）比较全国四大区域，东部地区增速最快，中西部地区速度稍慢。计算分散度变化与城乡建设面积变化的比值（计为CD），发现东部地区单位城乡建设用地变化所导致的分散度变化在增长，但增加幅度不大。值得注意的是，中部地区的CD值大幅上升，说明处在快速发展初期的中部地区，分散度增加更为迅速；（3）从省际差异和区县差异看，2000-2010年城乡建设用地变化较大的区域主要分布在大城市群附近，分散度变化较大的省份主要集中在浙江、福建、重庆和广东，同时主要大城市和主要矿业城市周围区县的分散度变化较高。 为了进一步理解城乡建设用地的分散分布机理，本文从行政区划、社会经济、政策因素、土地法律法规、全球化等方面选择了13个指标，应用空间计量模型分析了不同区域的城乡建设用地分散度变化的驱动因素。回归结果显示，在东部地区城乡建设用地的分散度的变化与土地隐漏违法案件比重呈负相关，而在中西部地区，这一关系反转为正。这进一步说明，在东部地区，严格的土地管控开始对城乡建设用地的分散程度起到一定的正向作用；然而在中西部地区，由于尚处在发展初期，快速发展的地区因用地转化多，往往代表更多的土地违法情况出现，所以呈现正相关。 综上，2000年以来，我国城乡建设用地分散情况更加突出，尤以发展初期、管理规划相对薄弱的中西部地区问题更为显著，而较为严格的土地利用规划管理可以减轻分散状况。这迫切要求我们关注用地的分散状况，加强相关的规划管理，尤其是针对那些发展初期、快速发展、且规划管理不严格的区域。

Urban and rural construction land is an important part of land use, and it is the most profound aspect of human activities for natural changes. The rapid development of industrialization and urbanization in China has transformed a large number of agricultural land into non-agricultural construction land. During this process, the scattered distribution of non-agricultural construction land in urban and rural areas is extremely prominent. The scattered distribution of urban and rural land will increase the cost of infrastructure construction, increase the difficulty of environmental protection, and aggravate resource constraints. Therefore, the decentralized distribution of research land and its mechanism are of great significance for China to achieve sustainable growth. However, most current studies on land use focus on the transformation of land use in urban and rural areas and its influencing factors, and less focused on the decentralization of urban and rural construction land and its mechanism. This paper uses GIS as a technical means to analyze the decentralized distribution of urban and rural construction land from 1990 to 2010 using quantitative and quantitative methods from the perspective of time and space. The results show that: (1) 1990-2010, The dispersal degree of construction land in urban and rural areas in China has increased, which has increased by 11.34%. The rate of dispersion expansion accelerated from 4% in 1990-2000 to 7% in 2000-2010; (2) Compared with the four major regions in the country, the growth rate in the eastern region is the fastest, and that in the central and western regions is slightly slower. Calculating the ratio of the change in the degree of dispersion to the change in the area of urban and rural construction (calculated as CD), it was found that the change in the degree of dispersion of urban and rural construction land in the eastern region was increasing, but the increase was modest. It is worth noting that the CD value in the central region has risen sharply, indicating that it is in the middle of the rapid development period and the dispersion increases more rapidly; (3) Judging from differences between provinces and counties, the areas with large changes in urban and rural construction land from 2000 to 2010 are mainly distributed in the vicinity of urban agglomerations, and the provinces with large changes in the degree of dispersion are mainly concentrated in Zhejiang, Fujian, Chongqing, and Guangdong. At the same time, the decentralization of major cities and major mining cities has a high degree of dispersion. In order to further understand the mechanism of decentralized distribution of urban and rural construction land, 13 indicators were selected from the aspects of administrative division, social economy, policy factors, land laws and regulations, and globalization. The spatial econometric model was used to analyze the driver of change of the dispersal of urban and rural construction sites in different regions. The regression results showed that the change in the degree of dispersion of urban and rural construction land in the eastern region was negatively correlated with the proportion of illegal cases of land escaping, while in the central and western regions, the relationship was reversed positively. This further shows that in the eastern region, strict land management began to play a positive role in the decentralization of land for urban and rural construction; however, in the central and western regions, due to the early stage of development, the rapid development of the area due to the transformation of land, Often representing more illegal land conditions, so there is a positive correlation. In summary, since 2000, the decentralization of construction land in urban and rural areas in China has become more prominent, especially in the central and western regions where development is relatively early and the management plan is relatively weak. The more stringent land use planning and management can reduce the decentralized situation. This urgently requires us to pay attention to the decentralized situation of land use and to strengthen related planning and management, especially for those areas that are in early development, rapid development, and lack of strict planning and management.