Abstract: Fuzzy character widely exists in rock and soil mechanical parameters used for the analysis of slope engineering. Fuzzy finite element method was developed to describe the response of fuzzy character to soil and rock structure. A new faster solution for governing equations of finite element method was put forward to decrease time of computation. Finally fuzzy finite element method was adopted to analyze a slope in Xiangjiaba hydro-electrical project. Case study indicates that the stresses and displacements of the slope are fuzzy variables as a response to fuzzy character of mechanical parameters. The results obtained by fuzzy finite element method could help engineer to know more about the distribution of stress and displacement, and about safety factors of slope than the certain finite element method. Because of more possibility of parameters being considered, the fuzzy finite element method could also decrease the decision risk due to the fuzzy character of mechanics parameters.