Water is a big issue in the world. As we enter the 21st century, a global water crisis threatens the security, stability and environmental sustainability of all nations, particularly those in the developing world. The Inter-Academy Council （IAC） proposed to undertake a study of the current and emerging challenges and opportunities for sustainable water resources management at its 2009 Board meeting. This paper gives a perspective of the IAC Water Program, and the case studies conducted by China Working Group of the IAC Water Program on three key issues, namely climate change ＆ water adaptive management, agricultural water ＆ ecology, and urban water ＆ environment. The purpose is to show the role of science ＆ technology for sustainable water in China. These studies are the 1st phase of the IAC Water Program in China. Perspectives of new challenges and opportunities on this Program for the water future in the world and China are also given in the paper.