Abstract: In Xingshan iron mine, the faults and fractures are very developed, which includes several big tectonic structures, such as fault F₉. So, stability analysis of the rockmass is necessary. Based on investigation of the engineering geological condition and weak structures, the stereo-analytical method based on block theory is used to analyze the movable blocks in rockmass formed under influence of fault F₉ and joints J₁, J₂ during excavation of roadways. The sliding mode of the movable blocks is also studied. The study on sliding mode of the movable blocks provides a basis for prediction of failure and support design of the rockmass.