Abstract:

Along with the socio-economic development， the various contacts between cities and regions are becoming more and more close and complicated. Although the research on regional characteristic and difference was dominant in geography thoroughly， traditional positive research on economic location and contacts was weak in quantitative methods， one of the main reasons was the shortage of statistic data. However， more and more researchers are studying in this field and many methods and techniques have been explored. They study it from different aspects and scales using quantitative and qualitative methods. City is an open system， and we can not imagine that a city can not develop if it has no contact with other cities. Research on the main direction of city economic contact is important to the city and region's development. This paper has researched on the main direction of city economic contact of central cities in Jiangsu and Zhejiang provinces and the city of Shanghai. With the aid of the gravity model， we calculated the foreign economic contact intensity of important central cities in Jiangsu and Zhejiang provinces and the city of Shanghai mostly by using the research methods of nodes analysis，transport network analysis and interaction strength analysis and so on. Supplemented by these indices， we can quantifiably analyze and point out the hierarchical characteristics of the economic contact spatial structure of Shanghai metropolitan area. It is found out that the foreign economic contacts intensity of important central cities in Jiangsu and Zhejiang provinces and the city of Shanghai is becoming higher and higher， and the difference between them is larger and larger， which indicate that the direction and route of the contact axes are regular and accord with the foreign economic contact intensity？ The foreign economic contact intensity of Shanghai is powerful and follows the rule of distance decay， which leads to a regional layered spatial structure. The inner economic contact intensity of Suzhou-Wuxi-Changzhou economic circle is very close. The foreign economic contact intensity of Nanjing and Hangzhou is not very powerful ，and its central status should be boosted as soon as possible. Transportation is the uppermost obstacle to weaken the foreign economic contact intensity of Ningbo. In a word， as to the foreign economic contact intensity， the economic level of the important central cities in Jiangsu and Zhejiang provinces and the city of Shanghai region is the essential qualification. Improving the condition of transportation， especially the freeway construction， is the critical factor to improve the development of economy， and also the one of leading methods to strengthen the economic contact intensity between regions. Of course， there are many other factors， which influence the intensity of the economic contact， such as distance， administrative regionalization， history and so on. Finally， we evaluate the foreign economic contact intensity of important central cities in Jiangsu and Zhejiang provinces and the city of Shanghai and put forward some relevant advices and measures.

Key words: central cities, Jiangsu and Zhejiang provinces and the city of Shanghai, the economic contact intensity, the foreign economic contact