System coupling of mountainoasisdesert plays a key role in the protection of water resource in Qilianshan mountains

River systems originating from Qilian Mountains have been supporting the existence of the mountain-oasis-desert ecosystem in the Hexi corridor. However, the productive pressure and the global climate change put this ecosystem into a crisis. The integration of forest, herbage, shrub, and moss play a key role in the protection of quantity and quality of water source as well as in the conservation of ecological environment in Qilianshan Mountains. The mountains, oasis and desert take effects as a whole. Out of order of any of which would cause a disaster of the agricultural system. Based on the theory of Four Production Level of Paratacultural System, optimization of productive structure will take a shortcut of system coupling of mountainoasisdesert, which establishes the agricultural system for water resource conservation the agricultural system foundation. The kind of pattern supplies a demonstration for inner land area of the whole world.