Abstract: In this paper, according to the present researches on water resource in the Hexi Corridor which are considered to confirm to radlity, the author has calcu-lated in detail the actual annual runoffs of rivers, the annual irrigation require-ments and actual water resources of the oasis scattered in every district and municipality.And also based on the actual water resource and indices of water requirements of farmland and oasis every year, the areas suitable for the oasis and farmlands have been determined on condition that naturaly ecological balance can be preserved.