Abstract: On the basis of direct shear tests, influence of asperity inclination angle on deformation and strength of a structural plane are examined. Structural planes of four asperity inclination angles are made using steel mould and concrete, and direct shear tests are conducted six times under five normal stresses. At the same time, shear stress and normal displacement are recorded. The analysis of shear stress-horizontal displacement and vertical displacement-horizontal displacement curve shows that the normal stress and asperity inclination angle become larger firstly and the structural plane is easier to be cut. For the same shear failure style, if the normal stress increases, the structural plane will be worn or cut more seriously, and the maximum vertical displacement is lower. If the asperity inclination angle increases, the zig-zag pattern will be worn or cut more seriously. From the second shear time, the structural plane is worn every time and is not affected by the normal stress and asperity inclination angle.