Abstract: The Yangtze River delta is one of the most developed regions in China. With the rapid development of urbanization, impervious areas spread quickly, and drainage networks decline gradually, which have greatly Influenced regional hydrology and water resources. The water quality is getting worse and worse. The flood and drought disasters have aggravated. Human living environment has changed and consequently sustainable development of economy is restricted. Taking several typical urbanizing areas in the Yangtze River delta as an example, this paper probes into the hydrological response of urbanization to hydrologic cycle and hydrological processes with the support of RS and GIS. The research centers on the impacts of urbanization on precipitation, hydrological process, river network, water environment and experimental observation of storm-runoff in the cities. Based on the above analysis, the characteristics of hydrological process under changing environment is modeled and predicted, and the utilization and protection of water resources is also addressed. The results of this study can provide useful support for regional economic development, flood prevention and water security.