The　joint　interface　plays　a　significant　role　in　machine　tools　and　other　machineries.　A　novel　type　of　joint　which　consists　of　oily　porous　material　was　proposed.　The　equivalent　stiffness　and　damping　of　oily　porous　joint　could　be　divided　into　solid　and　liquid　parts,　and　the　two　parts　are　shunt　connection.　Theoretically,　the　stiffness　and　damping　of　solid　part　were　established　using　Hertz　contact　and　fractal　theory,　and　the　liquid　counterpart　was　also　deduced　from　the　average　flow　of　generalized　Reynolds　equation　through　a　correlation　parameter　A　(r).　It　was　concluded　from　simulation　and　calculation　that　the　total　equivalent　stiffness　of　oily　joint　is　increased　with　D　and　decreased　with　increased　G.　The　experiment　was　carried　out　to　compare　the　normal　characteristics　of　porous　material-steel　oily　joint　with　non-media　steel-steel　joint,　and　the　result　was　that　the　joint　which　contains　an　oil　film　interlayer　formed　by　porous　and　steel　is　superior　to　the　joint　with　non-media　formed　by　steel　in　stiffness　and　damping　characteristics.　In　the　case　of　the　same　preload,　the　former＇s　stiffness　is　increased　by　about　30　%,　and　the　damping　is　increased　about　five　to　six　times　meanwhile.