Abstract: On the base of the index of per capita GDP at county scale in Jiangsu, theil index during 1990-2011 is measured, by the method of combining spatial autocorrelation and statistic analysis, spatial-temporal pattern and mechanism of county economic in Jiangsu are discussed. The results show that: the total economic disparities of county economic in Jiangsu Province have enlarged, the integral economic disparities of county level in Jiangsu are bred by the disparity among North Jiangsu, South Jiangsu, Middle Jiangsu and the disparities inside North Jiangsu and inside South Jiangsu; there is a strong element of economic development spatial autocorrelation, meaning that the economy of counties which around the economically developed counties are often more developed, and the accumulation state is more and more obvious; local space pattern performs the circle-shaped space distribution structure that Suzhou, Wuxi are the core; the Jiangsu spatial economy framework tends to be more continuous and self-organized, the random of the spatial differential pattern keeps decreasing and the mechanism of the structural differentiation caused by natural correlation in space is becoming more and more remarkable; the homogeneousness of economy development in the direction of southeast-northwest is typical for its relatively small spatial difference, as to the opposite direction, the spatial difference is great. Last, the paper put forward some suggestions to promote county economy development.