Abstract: Based on the variable analysis of Chinese north and south grain transfer and combined agricultural water footprint theory, this paper puts forward that at the same time of implementing South-to-North water diversion entity engineering construction, the “agricultural North-to-South water diversion virtual engineering” has been formed and carried out since 1990. The calculating results showed that: this engineering has transferred over 20 billion cubic meters virtual water from 1990 to 2008, which was much more than transfer scale of South-to-North water diversion entity engineering. The water transfer amount of North-to-South water diversion virtual engineering showed an overall increasing tendency, it was hard to support food production in northern China only by South-to-North water diversion entity engineering, so it became a only solution for this problem to vigorously develop modern water-saving agriculture and improve the comprehensive water efficiency of food production by using technology. Considering the realistic gap of economic condition between south and north China and the extended service of South-to-North agriculture water diversion, researchers suggested that, implementing regional virtual water trade strategy, at the same time, reinforcing the research of the evolution and management of regional agricultural water footprint, making relevant technical standards of regional agricultural water footprint. It will provide scientific basis and policy support for implementation of the regional virtual water trade.