中文摘要：

在ArcGIS软件和江西省基础地理数据支持下，对城市群空间结构效益的定义和内涵进行了初步解析，从城市群规模效益、城市群距离效益及城市群空间联系效益3个方面对环鄱阳湖城市群方案和大南昌城市群方案进行了比较研究。结果表明：环鄱阳湖城市群的突出优势在于城市数量较多，人口规模较大，但是其紧凑度过低，城市规模等级结构优势不够明显，空间可达性较差，重要城市之间的空间联系不够紧密，呈现较明显的“大而空”特征；大南昌城市群紧凑度较高，城市规模等级结构优势度相对较高，可达性较好，重要城市之间的空间联系较为紧密，但城市数量较少，人口规模较小，规模效益相对欠缺。以实现城市群空间结构效益最大化为目标，在综合分析的基础上提出了南昌城市群方案。

英文摘要：

Spatial structure benefits of urban agglomerations have critical impacts on the overall development of urban agglomerations. Thanks to the help of ArcGIS and basic geographic data, spatial structure benefits of urban agglomerations have been defined and expounded in this article. Then, the comparative study between Poyang Lake urban agglomeration and the Great Nanchang urban agglomeration has been conducted from 3 as- pects, that is, scale merit, distance effect and spatial association benefit. The research results show that： Poyang Lake urban agglomeration has its outstanding strengths which are larger number of cities and bigger popula- tion size, however, some shortcomings of lower compactness, unobvious city hierarchical structure, poor spa- tial accessibility and weak spatial connection between some important cities coexist. Therefore, the Poyang Lake urban agglomeration exhibits a characteristic of ＂big ＆ empty＂. On the contrary, the Great Nanchang ur- ban agglomeration which has fewer number of cities, smaller population size and poor economies of scale, presents the highlights of higher compactness, obvious urban hierarchical structure, better spatial accessibility and good spatial connection. In order to maximize the spatial structure benefits of urban agglomeration, basing on the comprehensive analysis, a programme of Nanchang urban agglomeration is put forward.