Abstract: Over the last decades, there has been considerable interest in the analysis of regional spatio-temporal pattern. Indeed, regional growth has exhibited complex spatial patterns including both population spread and economic equity decentralization from the well-developed counties to the less developed ones. Regional disparity is an important issue to the regional study in revealing the discrepancy of related regions and thus to display the spatial pattern between regions. And interregional disparities in China’s economic development have attracted considerable political and scholarly attention. Although in a country of such a vast size as China, large disparities seem to be an unavoidable fact of nature, there is the additional impact of distorting policy interventions and spatially divergent institutional change, which renders the topic analytically very difficult and fiscally sensitive. In recent years, a host of studies have been devoted to this topic, with an increasing degree of analytical sophistication. This paper takes per capita GDP as the measurable index, whose data was derived from the economic belt along Lan-Xin Railway. That region consists of 114 administrative counties from which the first and the ongoing second double-line of Lan-Xin Railway buffers 150 kilometers away. In order to reveal the spatio-temporal distribution patterns and spatial interaction types of economic disparities in the economic belt along Lan-Xin Railway, between 2000 and 2009, traditional statistic analysis, which is often used as a tool to reveal the disparities within regions, and spatial autocorrelation analysis that is helpful in taking the geographical location into consideration to make up for the shortcomings of former methods, are combined together to reveal the economic disparities of research units. The conclusions are as follows: the absolute disparity of per capita GDP for administrative counties increased constantly, while the economic concentration of those research units declined with fluctuations and the economic disparities along the Gansu part of Lan-Xin Railway accounts for the largest part of the whole economic belt along Lan-Xin Railway, where the disparities of intra-Gansu Province grows bigger and that of the inter-regions is getting smaller. The higher level developed counties mainly locate on northern slope of the Tianshan Mountains, and the western part of Hexi Corridor which covers from Zhangye City to Jiayuguan City along the Lan-Xin Railway, and those high level counties cluster at intervals; while, the lower level developed counties mainly concentrates in the central part of Gansu Province, the eastern part of Hexi Corridor and the eastern part of Qinghai Province, and as to the rapid growth counties, it is obvious to find the trend of agglomeration beside the Tianshan Mountains. The spatial interaction within research units is weak, while the northern slope economic belt and southern slope industries belt of the Tianshan Mountains which takes the Urumqi City as center city keep great economic growth condition; the central part of Gansu Province and the eastern part of Qinghai Province is not developed very well and that of the polar cities which are Lanzhou city and Xining City respectively have a little radiation effect to lead and foster the neighboring counties economy.

Key words: regional economic disparity, spatio-temporal pattern, ESDA, GIS, the economic belt along the Lan-Xin Railway