The paper analyzes the temporal-spatial characteristics and its momentums of China's urbanization during transitional phase by GIS and the statistical methods. In contrast to the regional urbanization levels and its growth with series data, it can be seem that China's primary urbanization level is lower and the speed is quicker than those of the World, developed countries and developing countries. With CCR(Comparative Changing Rate) of China's urbanization during 1985-2003 calculated and GIS employed, it is obvious that the provincial disparity of China's urbanization is serious. On the basis of statistic way, the major momentums of urbanization during transitional phase have also been researched. Though PCA(Principle Component Analysis), the results show that the factor of industry-agriculture pushing and towing, the factor of industrial structure shifting, and the factor of export-oriented substituting are three major momentums, which had been affected China's urbanization development. But the influential forces are different among three belts, with Bivariate Correlation Analysis and Stepwise Regression Analysis availed, the researched results reveal that the major factors in the eastern belt are the tertiary industry, industry shifting ability as well as export-oriented economy, and the level of tertiary industry is the most significant; the major factors in the middle belt are the large & medium-sized enterprises distribution, industrial and agricultural development; the major factor in the western belt is the level of industrial development.