Abstract: For the engineering of the concealed goaf under the open slope, a three-dimensional model of the concealed goaf slop was created using AutoCAD, ANSYS and FLAC^3D with their respective advantages. The influences of concealed goaf slop under conditions of two different locations were analyzed utilizing Mohr circle which is intuitive and efficient to teflect the state of slope stability. The research shows that the open slope is unstable when the concealed goaf locates the upper open slope. A relative stable slope exists when the concealed goaf locates in the lower part of open slope.