The urban spatial morphology has always been the core field research focus of urban geography. Large city morphology evolution is the result of long-term social and economic development. The dramatic changes of China’s urban spatial form have brought many problems in economic, social, urban construction and urban environment. To understand the progress and mechanism of urban spatial morphology changes, building appropriate quantitative assessment model for urban spatial morphology is significant for promoting China’s sustainable urban development. Since the 1990s, there are new economic and social backgrounds in China. Due to the new mechanism and dynamic characteristics of urban morphology evolution, it is very important to get some new conclusion for the amendment of city theories. This paper summarizes the current research gaps on the basis of narrating the research progress about the evolution of urban form at home and abroad. Then, it chooses 35 Chinese provincial capital cities or above, analyzed the spatial-temporal characteristics of cities’spatial morphologic evolution in recent 20 years not only with the help of multi-temporal Landsat TM/ETM+ remote sensing satellite imagery,urban land use planning map, socio-economic statistical data and other relevant information, but also with ArcGIS 9.3 software platform and Erdas 9.2 software and some different research methods, such as statistical analysis, Boyce-Clark shape indices, compactness indices,trend analysis. The results show that, during the period from 1990 to 2010, the expansion speed of the eastern cities is higher than that of the western and central cities. Among them,the expansion rate of the four municipalities is generally higher than other cities. Relatively slow expansion cities are mainly located in heavy industrial or valley-pattern cities of North and Northwest China. The shapes of the 35 cities are mostly in-between the square and the rectangle in the period from 1990 to 2010, only a few cities in the shape of the diamond, star, H-shaped or X-shaped. Out of 35 cities, 15 cities showed a decreased trend in compactness indices and 20 cities showed an increased trend from 1990 to 2010. The range of shape indices for Chinese cities varies from 6.82 to 69.32 in 1990 and from 7.56 to 65.81 in 2010. Generally, the averages of the shape indices in the two years are 24.9 and 32.09 respectively, which indicated urban morphology tends to be more complicated. The major way of urban morphology evolution of provincial capital cities or above in China is the intension-type development instead of extension transit during the period of 1990-2010. The urban morphology evolution is the result of both inner and outer driving forces, indicating the complexity of urban morphology evolution. This research is highly valued for planning administration and planning practicality, especially at such a high speed of urban expansion and well-developed city planning in China.