利用中国19个城市群面板数据，基于多维指标测度城市综合规模并估算城市群空间结构，进一步识别空间结构对城市群经济发展的影响。研究发现，总体上单中心结构显著促进城市群经济发展水平提升；异质性分析表明，在城市化率、经济发展水平或创新水平均较高的城市群中，单中心结构对城市群经济发展具有显著正向影响；分区域来看，在东部和东北地区，多中心结构显著促进城市群经济发展，而在中部和西部地区，单中心结构则更有利于城市群经济发展。上述结果说明我国实现城市群的“中心开花”，即由单中心转向多中心、多层级网络型城市群尚需各方共同努力。

The development of city-clusters is not only the focus of regionally coordinated development and a major regional strategy, but also an important part of China's new urbanization strategy. Spatial structure and regional economic development have become the key issues in formulating regional development policies for the Chinese government. On one hand, it is necessary to further differentiate and analyze the spatial structure characteristics of the 19 city-clusters in China; and on the other hand, it is also vital to explore the impact of spatial structure characteristics on the economic development of urban agglomerations based on actual situations. However, the published works on the impact of spatial structure on regional economic performance have not reached consistent conclusions, and there are few literatures that discuss the impact of spatial structure on regional economic development at the level of city-clusters.#br#Using the panel data of 19 city-clusters in China, this paper applies the rank-size rule to calculate the spatial structure of city-clusters based on multidimensional indicators, and explores the impact of spatial structure on the economic development of city-clusters by the classic OLS estimation model. The relevant indicators used for estimation include the weighted average GDP of each city in the city-clusters, the spatial structure of the urban agglomeration, and control variables like the average population of each city in the city-clusters, the urbanization rate , science and technology expenditure, the number of people engaged in the scientific comprehensive service industry , etc .#br#It is found that the monocentric structure significantly promotes the economic development level of city-clusters in general, and the heterogeneity analysis shows that in city-clusters with a high level of monocentric spatial structure, urbanization rate, economic development, and innovation, the monocentric structure has a positive impact on regional economic development. While the regional heterogeneity shows that in the eastern and northeast regions of China, the polycentric structure of city-clusters significantly promotes regional economic development, while in the central and western regions, the monocentric structure of city-clusters is more conducive to economic development, which means that it still requires the joint efforts of all parties to achieve the "center blossoming" of transformation from monocentric to polycentric and multi-level network city-clusters.#br#Specific suggestions are provided. In the eastern region of China with a high level of urbanization, the concentration of production factors in the first central city may improve the development of the central city itself, but the regional heterogeneity analysis shows that the monocentric structure has inhibited the economic development of city-clusters, while the polycentric structure is more favorable to the economic development of city-clusters. Hence, local governments should guide production factors to gather in sub-center cities, create multiple growth poles in the region, promote the formation of multi-center, multi-level, and multi-node network-type city clusters, and promote multiple central cities to jointly drive regional economic development. There is still a large gap between the development level of city-clusters in the central and western regions and the eastern regions, and the monocentric spatial structure can still play a greater role in driving the economic development of city-clusters. Therefore, the local government should increase policy support for the first central city, and appropriately implement the "strong provincial capital strategy" and other measures to encourage the development of large cities, promote the further concentration of labor, capital and resources and other factors of production in the first central city, and play the radiation effect to drive the economic development of urban clusters. In the northeast region of China, the polycentric structure of city-clusters has also significantly contributed to the improvement of regional economic development. Thus, local governments should encourage and guide production factors to concentrate in sub-centers, and appropriately create a dual-centric or polycentric structure of urban clusters, so that multiple central cities can lead regional economic development.#br#