According to the regionalism in 1990, this paper takes the urban district of each prefecture level city and county (city) region in Jiangsu as the absolute research unit, and there are 76 research units point region(PR) Every research unit is acted as the point factor to research the regional spatial structure (RSS) By studying the evolution of every PR, the relationship between the regional development (RD) and RSS are established To proceed from the difference of these points in development, this paper chooses 19 indexes of every county in 1980, 1990 and 2000 in Jiangsu, and uses the method of rotated factor loading matrix to get the comprehensive strength evolution of RD of every research unit in different periods In the light of this, the cause of RD of spatial structure evolution is analyzed The research result shows that the change of spatial elements is different in different phases; regions are the main change factors in the 1980s, meanwhile the main change factors are points in the 1990s The difference of RD leads to the transformation of spatial factors, and consequently to the change of RSS RD is the essential reason causing the change of RSS, and the change of the regional spatial factors especially that of point is the direct reason causing the change of RSS Finally, the spatial mechanism of region developing discrepancy in Jiangsu is expounded in this paper Inclination to Sunan of RD in space is apparent in Jingsu According to the distribution of research units in different districts during different period, the cities in Sunan(southern Jiangsu) mainly focus on the third class, the cities in Suzhong(central Jiangsu)mainly focus on the fourth and fifth classes, and the cities in Subei (northern Jiangsu) mainly focus on the sixth class At present, the developmental difference of each axis is obvious, the one along the Yangtze River being the main axis, and the driving effect of East Longhai axis, Subei canal axis and coastal axis are indistinctive At the same time, the developing degree of spatial structure in each region is different Taking the Shanghai Nanjing railway as the main axis, the southern,central and northern part of Jiangsu is respectively in the developing stage from the axis to network, from the point to axis and growth pole