Based on the FLAC2D finite difference software, strength reduction theory has been used 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 set up, the elements of which are then 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 determined. 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 effeetively design of the actual slope works.