There are a large number of cracks, joints and layers with different scales and orientations in the rock masses. With the structural formation in it, the rock mass is unlike the isotropic and homogenous materials in physics and mechanics characteristics, and the failure of the rock mass is controlled by those discontinuities. This paper studies the stability of a jointed rock slope with bedding-planes. Universal Distinct Element Code (UDEC) is used to carry out the numerical analysis. The factor of safety (FOS) and failure mode are obtained by strength reduction technique before and after the steel bolts are installed in the slope. In addition, the forces along the bolts indicate that they reaches the maximum value in the potential slip surface of the slope.