Abstract: Based on the systemic analysis method and the preferred plane theory in rock-soil mass,the concept of storage and movement effect of water on rock-soil preferred structural plane is put forward,and its application is studied.The following conclusions can be drawn.Firstly,there are different kinds of structural planes in rock-soil,and the stability and infiltration problems of rock-soil can be induced by the structural planes.Secondly,after confirming the preferred structural plane,preferred location and preferred depth of well,the finding out of underground water can be ensured.Thirdly,the water emerging in underground engineering has close relation with the structural plane.But only when the structural plane possesses some preferred index,such as time,dimension,it can lead to water-emerging.Finally,the interaction of water and preferred planes can induce the sliding of slope and infiltration destruction of dykes.