Abstract: By analysis on the monitoring data of suspended concrete impervious wall under construction of Renzonghai hydropower station, including the wall deflection, seepage pressure of different elevation upstream and downstream the wall and the vertical strain along the wall depth, conclusion was gotten that the wall deflection was related to the dam filling, and largely effected by the horizontal thrust caused by dam body weight.The impervious wall was effective, but by pass seepage was found towards downstream.Vertical load and wall lateral friction exerted influence on the spatial distribution characteristic of wall strain.In detail, tension strain was found at the shallow wall, as wall depth increase, it decreased and turned to compressive strain, and the maximum strain appeared at the wall bottom.