Abstract: The authors carried out the evaluation and study of the regional crustal stability and geological hazards in Xi'an City. A wealth of data was gained in geology, geophysical prospecting, surveying and model experiments. According to an analysis of these data and considering such factors as the endogenic and exogenic dynamic geological processes and medium conditions, six principal factors affecting the crustal stability in Xi'an City are selected as a system of the stability evaluation indicators and the fuzzy mathematic method is applied to make a regional crustal stability evaluation. The authors divide the crustal stability in Xi'an City into three grades, sub-unstable, relatively unstable and unstable, and ten areas. On that basis, some guidance suggestions for the urban construction and development plan in Xi'an City are put forward in this paper.