Understanding the closure behaviour of rock fractures is of great importance for various rock mechanics and rock engineering issues such as geothermal energy extraction, carbon dioxide capture and sequestration, and geological disposal of radioactive waste. The stress acting on a single bridging asperity results in the surface deformation of itself and the surrounding areas. The aggregate of such deformations exerted by all contacting asperities leads to the total deformation of a fracture. Therefore, the deformation behaviour of a stressed fracture is governed by the mechanical properties of the intact rock (elastic modulus and strength) and the geometrical characteristics of asperities (spatial distribution and local shapes). A contacting asperity may fail when the local stresses have reached some failure criterions, which is responsible to the hysteresis observed in cyclic loading experiments. In the present study, a high-precision contact model that used Boussinesq's solution to relate contact stresses to surface displacements in two half-spaces was employed to calculate the deformation of rock fractures subject to normal loading-unloading cycles. The normal stress-displacement curves of cyclic loading experiment are in good agreement with the calculation results, and the measured surface damage area fits well the calculated plastic area, which efficiently verifies the validity of the numerical calculation model. An extended parametric study that considered more patterns of dislocation degree was implemented and the numerical calculation results show that the normal stress-displacement curves of different loading cycles show obvious hysterical behaviour. The hysteresis indicated that damages happened on partial contacting asperities, which tended to enhance the closure of a fracture. The hysteresis generated by a loading cycle is typically less than the previous one, showing a gradual weakening trend. More specifically, the damage of the contacted asperities accumulates successively with the increase of loading cycles, and the damage tends to cease after several cycles. The damage-induced permanent change of surface geometry varies the mechanical behaviour of fractures. As the number of loading cycle increases, the normal stiffness of the rock fracture also tends to increase, and eventually approaches a stable value after 4∼5 loading cycles. The numerical calculation provides quantitative estimations on the deformation and asperity damages, which are direct evidence for the hysteretic behaviour of rock fractures subject to cyclic loadings.