Bolted　connections　are　widely　employed　to　fix　the　structural　components,　in　which　the　bolted　joint　is　one　of　the　weakest　parts　and　can　significantly　affect　the　dynamic　characteristics　of　the　machine　tool.　In　this　research,　a　stiffness　and　damping　model　based　on　the　uneven　surface　contact　pressure　is　presented　for　the　bolted　joint　to　accurately　predict　the　dynamic　characteristic　of　a　bolted　assembly.　The　normal　and　tangential　stiffness　and　damping　of　the　contact　surface　can　be　deduced　based　on　the　fractal　contact　theory.　However,　the　contact　surface　pressure　of　bolted　joint　is　unevenly　distributed　due　to　the　influence　of　the　concentrated　force　of　multi-bolts.　Therefore,　the　pressure　of　the　contact　surface　is　introduced　to　define　the　stiffness　and　damping　of　bolted　joint.　The　assumption　is　that　the　contact　surface　is　flat　in　the　macro-scale.　Then,　we　can　obtain　the　pressure　distribution　of　contact　surface　through　the　finite　element　(FE)　method.　The　nonlinear　relationship　of　stiffness,　the　damping　of　the　bolted　joint,　and　the　pressure　of　contact　surface　can　be　obtained　and　assigned　to　the　FE　model　based　on　the　pressure　distribution　of　the　contact　surface.　An　experimental　set-up　with　a　box-shaped　specimen　is　designed　for　validating　the　proposed　model.　The　equal　pre-tightening　force　and　bending　moment　effect　case　studies　are　provided　to　demonstrate　the　effectiveness　of　the　model.　The　results　show　that　the　proposed　model　can　be　used　to　accurately　predict　the　dynamic　characteristic　of　the　machine　tool.