The　fractal　models　of　the　real　joint　contact　area　and　the　contact　stiffness　based　on　the　modified　M-B　fractal　model　are　described　in　this　paper.　In　order　to　make　the　calculated　size　of　the　total　real　contact　area　is　closer　to　the　actual　contact　area,　the　three-dimension　surface　topography　and　the　elastic-plastic　deformation　are　both　considered　to　build　the　model　of　the　total　real　contact　area　and　the　corresponding　normal　contact　load　with　the　real　contact　area　of　single　asperity　as　integration　objects,　and　the　different　fractal　dimensions＇　influence　on　the　contact　quality　of　joint　surface　is　revealed　by　using　MATLAB　simulation　software.