The acceleration of urbanization has prompted the economic development tremendously, but it also accelerates the consumption of the natural resource, It is clear that there is dialectic relationship between the urbanization and the sustainable development. In this article, the author creates a coordinated index model of regional urbanization and sustainable development, and using it to analyze the case of Changsha-- Zhuzhou--Xiangtan megalopolis. The conclusion indicates there is a favorable harmonious relationship between urbanization and sustainable development in the region.