Abstract：Anti-slide pile is an important method for slope treatment，especially when the slide face is certain and the subterrane is stable，the method is proved to be prior. But if there exist more weak terrains under the slide face， a new slide face may be formulated after being reinforced and ideal reinforcement effect can not be achieved. Monitoring and analysis of anti-slide piles reinforcement effect on the west area slope of Chengchao Iron Ore are analyzed. The results indicate that there are shallow-layer and deep-layer slide faces in the slope after reinforcement. At first，there is only a shallow-layer slide face found before reinforcement，but a new weak face on the base of the first shallow-layer slide face is found after reinforcement and then，shallow-layer and deep-layer slide faces are found. However，anti-slide pile has effects only on the shallow-layer slide face because of its length. It is pointed out that the influence of ground water is an important factor for slope deformation.
