中文摘要：

在经济全球化和信息化的今天，城镇密集区已成为全球经济体系的重要节点区域。文章首先用定性判断和定量计算的方法对兰州-西宁城镇密集区空间范围进行界定，然后从城镇的中心职能强度、城镇间经济联系强度和城镇经济辐射的空间范围三方面，对密集区33个主要城镇的经济联系状况进行测算。主要结论有：城镇中心地位的高低与其人口规模、经济实力及社会经济发展整体水平相关；中小城镇竖向联系强，横向联系弱，城镇间经济联系表现出明显的地域临近性；城镇经济影响范围的大小与其中地位的高低相对应，经济影响区界线存在重叠现象。

英文摘要：

Nowadays,with the areas have been the important coming of economic globalization and informationization, city-and-town concentrated node areas in the global economic system. Firstly, the paper definites the spatial range of city-and-town concentrated area around Lanzhou - Xining by the means of qualitative analysis and quantitative calculation. Secondly, the condition of economic relationship was calculated and analyzed in thirty three main towns of the concentrated area, from three aspects of the central function intensity of city and town, the economic relationship intensity and the economic radioactive spatial range between city and town. The main conclusions are as follows ： the height of central position of city and town is related with population scale, economic strength and the whole level of social and economic development;there are closely vertical and remotely horizontal relationships between small and medium-sized city and town, and the obvious area approaching is displayed in their economic relationship ; we have made a simple research on scope influenced by city-and-town economy, using the method of calculating gravity value between the two areas according to gravity model. The calculation and analysis based on economic relationship of city-and-town concentrated areas are the focus of this paper： the central function intensity of city-and- town was calculated with some indexes which characterize the economic strength and development level of city-and- town, and the hierarchy was divided. The economic relationship between city and town was analyzed, using the model of economic relationship intensity and subordinate degree. With the gravity model, we calculated the gravity value. And the scope influenced by city-and-town economy was analyzed systematically from the perspective of the mutual attraction between city and town. In the situation that the specific and influenced scope of city-and-town was not divided, it is an innovation that we use the Largest Gravity Line Chart and Gravity Value Sort T