Abstract: In this paper,A method for delineating wellhead protection areas,Krijgsman-Lobo-Ferreira method,is introduced and the formulas for calculating the protection distances of upgradient,downgradient and perpendicular to the direction of the groundwater flow are derived. The applicability and some complications about the formulas are also discussed. The method is applied to Zhangji area,Xuzhou city. The results show that it is a simple and effective method for identifying the wellhead protection area,and can be applied to other areas in China.