Abstract: This paper is the in-depth study and development of the Reference1. Based on results of the statistical analysis of a large amount of mearurod data in geotechnical engineering and civil engineering, the fundamental fuzzy model of rock (soil) mass displacement is established by using the theory of fuzzy probability measures.晈here P(A’) is the subsidence fuzzy probability; |,-, a/(i = 1,2,3,4, /= 1,2,3) are*? fuzzy parameters) ZH is a parameter depending on the mining (excavation) depth.This fuzzy model is universal and significant in geotechnical and civil engineering. The formulas derived in this paper have been confirmed by a large amount of measured data. The fuzzy model, therefore, is valid for solving the problems of the rock (soil) mass displacement and deformation due to underground excavation. This fuzzy model has been evolved into a new research system in roc k and soil mechanics.