Abstract: Because of the complex nature of rock （soil）mass in open -- pit mines, it is difficult to accurately measurevarious factors which have great effect on the slope stability. Based on results of the statistical analysis of a largeamount of measured data in geotechnical engineering and civil engineering, the fundamental fuzzy models of rock（soil） slope stability are established by using the theory of fuzzy measures. To calculate the rock（soil） mass stability,the rock （soil） mass is regarded as a macroscopically homogeneous and isotropic medium, and thus a new numericalmethod for analysing the fuzzy measure of rock （soil） slopes is derived. The practical calculation shows that themethod can be applied to analyze the problems of the rock （soil） mechanics.