The issue of inter-provincial economic zone has become one of the hot topics in the economic geography study. Based on SPSS software package and GIS technology, this paper makes a comprehensive analysis of the market economy development at county level, and reveals the characteristics and the laws of regional disparity about market economic development in Huaihai Economic Zone. Firstly, this paper introduces the development of Huaihai Economic Zone and the extent of academic domain. Then it makes a critical review on researches on regional market spatial distribution. Secondly, supported by software of SPSS and ArcGIS, the authors select 115 counties of Huaihai Economic Zone as research units, and use the data from statistical yearbooks of 2005 of Huaihai Economic Zone cities. Based on the review of the evolution of regional market space analysis, this paper draws some conclusions as follows. Factors mainly influencing Huaihai Economic Zone regional market differentiations are the production factors, with weight of 43.519%. Huaihai Economic Zone regional market overall development is low and the regional market differentiation is huge. The external economic market capacity of South Shandong is higher than that of North Jiangsu because of a lot of resource development and industrial development since 1990s, especially the construction of Rizhao and Lianyungang port. Thirdly, based on studies of the spatial distribution and the statistical analysis approach, the regional market of Huaihai Economic Zone can be divided into four areas including the most developed north regional market area, the developed south regional market area, the developing east regional market area, underdeveloped west regional market area. Finally, the paper makes a brief analysis of the basic characteristics of each regional market, and puts forward some suggestions for breaking down administrative barriers, overall planning coordinated development, strengthening the economic exchanges, so as to achieve comprehensive and harmonious development in the Huaihai Economic Zone.