From actual planning work on a number of small and medium eities of China.research methods on regional economico-geographie foundation of city development maybe summarized as follows:1. The economie development of the region is the basis of city development. Themost important factors influencing city development are: (a) The political situationand need for national economic developments; (b) Geographical location, historical de-velopment and natural resources of the city and regional economic conditions. Cities,in their economic function are economic centers for areas of various extent. Therefore,the idea of city-region is, in fact, the conception of economic center-economic region. InChina, city-region implies the following two cases:(1) Administrative centers of various administrative units generally posses certainregional economic foundation and consequently serve as economic centers for certainregions.(2) The economic hinterland of certain cities may exceed their respectiveadministrative units.2. The main content of the studying regional economic development of a city is:(1) Foundamental characteristics of regional physico-guographical conditions andtheir areal differentiations.(2) Land, mineral and labour resources of the region.(3) Localization and development of agriculture of the region and its demand onthe eity.(4) Localization and development of industry of the region and its relation withthe city.(5) Transportation of the region, especially quantity and transport direction ofmain commodities which may be used to demarcate the extent of hinterland of the cityfrom the neighbouring economic centers.(6) The distribution of other small cities and towns in the region.(7) The economic position of the eity-region in a given province and the economicrelation with neighbouring regions.