The　shear　behaviour　of　rock　bolt　inserted　in　rough　joints,　with　the　JRC　ranging　from　0　to　18,　was　investigated　with　a　series　of　single　shear　tests.　The　results　indicated　that　the　shear　behaviour　of　rock　bolt　was　strongly　influenced　by　the　joint　roughness.　The　shear　resistance　reached　to　a　large　value　in　the　early　stage　for　most　case　of　rough　joints.　The　shear　dilatancy　of　bolted　rock　joints　was　smaller　than　the　ones　without　rock　bolt　for　the　same　JRC　condition.　A　dimensionless　mathematical　model　was　established　to　predict　the　shear　behaviour　of　rock　bolt　inserted　in　different　roughness　conditions.　As　the　contribution　of　rock　bolt　on　the　shear　resistance　has　a　nonlinear　relationship　with　the　joint　roughness,　whereas　the　maximum　shear　displacement　exhibits　good　linearity　with　a　high　correlation　coefficient.　The　maximum　shear　resistance　of　rock　bolt　was　evaluated　as　a　negative　exponential　function　of　JRC.　The　maximum　shear　displacement　of　rock　bolt　was　evaluated　as　a　linear　function　of　JRC.　Two　tests　with　natural　rough　joints　were　conducted　to　verify　the　applicability　of　the　proposed　mathematical　model.　The　predicted　values　of　maximum　rock　bolt　and　maximum　rock　bolt　indicated　good　agreement　with　the　test　results　with　an　average　estimation　error　of　8.3%.