In arid and semi-arid region, groundwater is one of the main water sources. The problems of water body pollution, shortage of water resources and unbalance of water ecology have made the paradox between the economy development and water safety more and more sharply. With the Xingping region as an example, by using DRASTIC method to select 7assessment factors such as groundwater depth, net recharge, aquifer media, soil media types, terrain slope, media types of the vadose zone, and hydraulic conductivity, the paper set up the index system of vulnerability of phreatic water and evaluated the regions vulnerability of phreatic water. The vulnerability of phreatic water in Xingping region is divided into poor and poorer grades. Partition map of vulnerability of phreatic water has been made. The result can provide a scientific basis for the development of regional industrial and agricultural production and urban planning.