Abstract: In this paper, a series of shear tests under different normal stresses were carried out on regular dentate rock mass discontinuities. The paper discusses the mechanical properties and main law of regular dentate rock mass discontinuity under shearing. Through the analysis of test data, it carries on further investigation on strength properties and roughness characteristics of discontinuities. On this basis, the shear stiffness model and the empirical relationship between climbing angle and roughness coefficient are proposed. Meanwhile, it carries on research to the shear curves of the discontinuities under the shear condition.