Abstract: This paper mainly describes the base principle of application the ²¹⁸P₀ method to seek crevice water of rock stratum,illust rates the base law of the trans-formation,concentration,storage,abundant radon and abundant water,poorly radon and poorly water,synchronous corresponding,and consitent position of water and radon under the fault zone condition,etc.,and introduces the curves types of high abnormal kurtosis and low abnormal hollow,and normal gently type,as well as their analysis method.The test and practice indicate that this seeking water method has the advantages of quick,accuracy,time-and labour-saving,etc.,and supplement other method to seek water and determine the well position,structuring well rate 98.2%.