Abstract: Based on the discrete element numerical simulation of rock slope，influences of the parameters (cohesion，internal friction angle，rigidity，dip angle，spacing) of rock structural plane to slope stability is studied to clear the influencing law for safety factor and failure modes of slope.According to the principle of variance analysis of orthogonal experiment，the significance that rock structural plane parameters impact on the slope stability is discussed.It is shown that slope safety factor is on linear growth in a certain range with strength of the rock structural plane increasing，and the failure modes shift gradually from the bedding sliding failure modes to the sliding-bending failure modes.The safety factors changes very little with the rigidity and spacing of rock structural plane increasing.Its maximum variance ratio is only 6.6% and 3.6%，and the slope failure modes are mainly sliding failure modes.Slope safety factor firstly decreases，then increases and finally decreases with the increase of the rock structural plane dip angle，and failure modes shift from shearing slip failure modes to shearing slip-buckling failure modes，finally to the tilting failure modes.The impact of the rock structural plane cohesion on the slope stability is the greatest，and the rigidity is the least.

Key words: Bedding slope, Rock structural plane, Orthogonal experiment, Safety factor, Failure mode