Abstract：The viaduct No.II of Shikongshan in Zhangzhou—Longyan expressway is located at a high slope with a complicated engineering geological condition. There are three sets of dominant structural plane J1，J2，J3 developed in the high slope rock mass. The combined slope plane with single dominant structural plane of rock mass，two sets of dominant structural plane and three sets of dominant structural plane，is analyzed by Stereographic projection respectively. The result shows that the natural slope is basically stable. Furthermore，the stability of slope to be excavated and natural slope is evaluated by SARMA limit equilibrium method，the high slope is also considered steady.
