Many　experiments　have　been　performed　to　study　the　mechanical　behavior　of　rock　bolts　in　resisting　the　shear　force.　However,　almost　all　the　tests　were　conducted　on　smooth　rock　joints,　which　is　inconsistent　with　the　field　engineering　practice.　In　this　paper,　the　shear　behavior　of　fully　encapsulated　rock　bolts　and　energy-absorbing　rock　bolts　inserted　in　the　rough　joints　was　investigated　with　a　series　of　single　shear　tests　under　constant　normal　load　(CNL)　conditions.　For　all　specimens,　when　the　value　of　JRC　increases　gradually,　the　value　of　peak　shear　stress　increases　gradually.　The　ultimate　shear　displacement　of　an　energy-absorbing　rock　bolt　is　larger　than　that　of　a　fully　encapsulated　rock　bolt　for　the　same　JRC　condition,　and　they　all　decrease　with　the　increase　of　JRC.　The　sensitivity　of　the　energy-absorbing　bolt　to　JRC　change　is　lower　than　a　fully　encapsulated　rock　bolt.　A　dimen-sionless　mathematical　model　was　established　to　predict　the　ultimate　shear　displacement　of　rock　bolts　inserted　in　different　roughness　conditions.　The　ultimate　shear　displacement　of　the　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　empirical　model　for　the　natural　rough　joints.　The　predicted　values　of　the　ultimate　shear　displacement　of　rock　bolts　indicated　good　agreement　with　the　test　results.　The　proposed　model　is　capable　of　providing　an　accurate　evaluation　of　the　ultimate　shear　displacement　of　rock　bolts　inserted　in　rough　joints.　The　results　of　the　laboratory　test　and　mathematical　model　all　show　that　the　energy-absorbing　bolt　can　bear　a　larger　shear　displacement　and　adapt　to　different　joint　roughness.