中文摘要：

空间集聚存在不同的尺度，城市区域作为当今具有较强竞争力的区域空间组织是一种大尺度的集聚。经典集聚理论、模型以及相关扩展性实证研究为城市区域尺度集聚的形成提供了方向性的暗示。这种集聚在本质上是聚集力和分散力动态组合的一种空间结果，其中，分散力的增强对城市区域尺度集聚的形成起到了重要的作用。随着区际运输成本的降低，核心区域一外围区域间共享的区际外部性逐渐增强；核心区域的拥挤效应进一步加强了经济活动向外围转移的倾向，最终促使部分经济活动突破地区边界，在地理邻近的地域之间形成更强的空间依赖，呈现出大尺度的经济集聚。城市区域尺度集聚的经济性为发展城市群、促进区域一体化提供了理论依据，但在实践中也遇到很多障碍，这对政府在打破行政割据、促进要素自由流动以及加强中心城市周边地区发展方面提出了要求。

英文摘要：

In recent years, domestic and foreign scholars increasingly believe that city- regions have much stronger competitiveness than other forms of regional organization. Classical theories, models, and related empirical researches have provided directional cues and interpreta- tion on relatively large scale agglomeration, such as city-region scale. Actually, the agglomeration is a comprehensive spatial result of both gathering and dispersion forces, where the dispersion force matters more. In this research, we concludes that with the reduction of inter-district trans- portation costs, inter-regional externalities will gradually increase, with the increasing crowding effects based on the overwhelming agglomeration as well, some economic activities tend to breakthrough administrative edge, spreading to surrounding neighborhood. Finally, a city-region scale economic concentration tends to present in the areas which are adjacent to each other. However, the city-region scale agglomeration has also met some obstacles in practice, such as ＂administrative economy＂ and ＂unmatched economic circumstances in the areas nearby＂. To promote the positive flow of elements, the government should break up the diseconomies of the administration division. At the same time, government should strengthen the construction of nearby areas＇ infrastructure in order to create better conditions to achieve maximum external scale in urban areas.