ABSTRACT
In a closed and conservative economic society, a country or a region could only rely on their own resources to achieve its development goals. However, in an open economic society, a country or a region could import goods produced by other countries or regions, and export goods produced by the rich local resources to achieve its development goals. To measure the amount of water resources invisible transfer caused by merchandise trade, it urgently needed an appropriate concept or a tool. The concept “virtual water” was just to meet this demand. And virtual water really played an important role in improving the efficiency of the global water resources allocation.
