Abstract: To fully understand the geological situation of open pit slope and obtain reliable rock mass mechanical parameters，the slope stability is analyzed.Combining with the geological information of east slope of Sijiaying Iron Mine，the technical means are adopted to enrich the geological information，such as field survey，geological drilling，borehole TV and other technical methods，and the joints and the rock mechanics information are obtained separately by 3GSM and the point load testing.Rock mass rating BQ classification and Generalized Hoek-Brown Strength Criterion are adopted to acquire the basic parameters for computation of slope stability.With the typical sections as a case，the slope safety factors are calculated out.The result show that the original designed final pit slope wall of the N9-N15 area of the east slope cannot reach the requirements of safety factors.The mine should pay attention to drainage and take necessary measures to ensure the stability of the east slope.

Key words: Open pit mine, Rock mechanics parameters, Slope stability analysis