Urgent challenges to water resources management for the next decade and beyond include Water Governance, Water & Food, Water & Nature, Water & Energy, and Water & Health including Sanitation, Water & Transboundary Cooperation and Climate Change & Adaptation, all of which are related to water security in regional & global scales. To respond to these challenges, water management strategies in both China and World need to address the two pillars of water demand management (WDM) and water supply management (WSM), broadly conceived, and the appropriate mix of WDM and WSM. This paper will address this urgent issue in global vision. By analysis, it was recommended as follows: at local level to carry out knowledge-transfer and exchange of the experiences and best practices about WSM; at country level to develop Guidelines for improving a joint WSM and WDM (eventually to be developed at river basin/district level). Since situations in each continent or sub—continent are very different, it is necessary to address specific Regional Guidance Reports including: a first Part, devoted to the assessment of available water resources and demands by using hydrological methods for estimating resources, and demand survey and predictions; a second Part on the organizations, institutions, tariffs and training and educational dimension of a joint WSM and WDM, at international level to develop a draft of an U.N. Convention oriented to foster a joint WSM and WDM for trans—boundary basins and/or under conditions of competitive uses and/or water scarcity. With reference to the above cited aims, the objectives could be limited on four aspects: WSM at local and country level (and short term); WDM at local and country level (and short term); Joint WSM and WDM at national level for medium and long term; Joint WSM and WDM at international/regional level for medium and long term.