Abstract: To enhance understanding of the mechanism of slope stability,this paper investigates some of the mechanical characteristics of the slope mass only subjected to its selfweight body force. It uses the FLAC numerical simulation software and similarity law. It studies the relationships between them and the related physical or mechanical parameters. At the ground surface,the principal stresses must be either parallel or normal to the topography in the absence of surface loads. As the depth increases,the principal stress directions approach either vertical or horizontal. There are tensile stress and compressive stress at the slope surface. And the tensile stress in the toe of a slope is also very high. These are some general characteristics for the distribution of stresses in a slope,shown both in this paper or some other articles. This paper emphasizes that when the angle of a slope increases linearly,the changing velocity of maximum tensile stress on the top of the slope behaves fastly,then slowly and then fastly. The tensile stress decreases linearly with the depth on a line from the top of the slope downward vertically to the inner of the slope. Under the condition of small deformation,the stress field does not depend on the Youngs modulus value. When meeting the similarity law,the magnitudes of displacement ratios at the corresponding points are square times of their sizes ratios of a slope. This paper complements to existing knowledge. It further offers a base for further studies on more complicated slopes. It is meaningful in both theory and practice．