Economic Spatial Structure Evolution and Optimization of Underdeveloped Provinces—A Case Study of Gansu Province
以甘肃为例，用因子分析法分析1995、2002、2010年14市经济发展水平，发现梯度空间结构，中心区集聚高于外围区，建议培育6个中心-外围城市群、改善基础设施和调整政策。
Taking Gansu province as the sample of underdeveloped provinces, this paper applies factor analysis method and analyzes 14 cities' evolutionary characteristics and pattern of spatial structure by their economic development levels in 1995, 2002 and 2010. Results show that: there has gradually formed gradient economic spatial structure in Gansu province from 1995 to 2010, which is made of central area(Jiayuguan, Lanzhou, Jinchang, Jiuquan), transition area(Pingliang, Tianshui, Wuwei, Baiying and Zhangye) and periphery area(Gannan, Qingyang, Longnan, Dingxi, Linxia).However, because the driving forces of central cities are weak and economic strengths of other cities increase slowly,there is an apparent spatial pattern, that center and western cities are better than southern cities in Gansu province, for the latter means poverty and drought areas. Thus the accumulation level of central area is higher than periphery area, and economic level of central area grows faster than periphery area. Therefore, in order to optimize regional economic spatial structure, narrow the development disparities of cities in Gansu province, the paper suggests that should foster 6 centreperiphery urban agglomerations, amend the infrastructure of periphery areas, adjust the orientation of regional finance and other policies.