The　stiffness　and　damping　modeling　of　joint　surfaces　are　important　for　analyzing　the　dynamic　characteristics　of　bolted　joints,　which　has　a　great　influence　on　the　working　precision　of　the　machine　tool.　In　this　paper,　a　damping　model　is　presented　to　predict　the　tangential　damping　of　the　joint　accurately.　The　fractal　theory　is　introduced　to　characterize　the　rough　contact　surface　by　using　fractal　dimension　D　and　fractal　roughness　parameter　G.　For　each　micro-contact,　the　contact　region　can　be　divided　into　stick　section　and　slip　one.　The　energy　dissipation　of　the　micro-contact,　which　can　be　described　as　the　tangential　damping　of　bolted　joint,　emerges　in　the　slip　section.　The　physics-based　friction　coefficient　is　introduced　to　define　the　energy　dissipation　function　based　on　the　relationship　between　the　deformation　of　micro-contact　and　the　normal　pressure.　The　energy　dissipation　factor　and　the　proportional　damping　of　the　micro-contact　can　be　obtained.　The　total　tangential　damping　of　bolted　joint　can　be　obtained　by　integrating　the　whole　contact　surfaces.　Experimental　set-up　is　designed　to　verify　the　proposed　model.　Compared　with　the　constant　friction　coefficient　damping　model,　the　results　show　that　the　proposed　model　can　more　accurately　describe　the　tangential　damping　of　bolted　joint.