Based on the FLAC2D finite difference software, We can use strength reduction theory to gained the stability factor of the 48 soil slopes under the different conditions, Grey Correlation Analysis Method of the Grey System Theory is employed to analyze the sensitivities of factor influencing slope stability. The matrix of correlation data is setup, the elements of which are transformed to dimensionless parameters. The grey correlative factors and grey correlative degrees which respect to the influencing factor and the slope stability factor are computed, and the sensible factors influence slope stability are decided. The results show that the cohesion of the soil. The density and the internal friction angle are the most sensitive factors to the slope stability, and the dilatancy angle, slope angle and the slope height are taken second place, which provide a reference to the reasonably and effectively design of the actual slope works.