A　thermo-mechanical　coupling　model　for　a　flat　plane　and　a　rough　surface　based　on　3-D　fractal　theory　was　established.　The　model　considered　the　interaction　between　asperities,　and　integrated　the　heat　flux　coupling　between　the　sliding　surfaces.　By　using　the　nonlinear　multiphysics　field　of　the　ANSYS　software,　the　frictional　sliding　process　of　the　elastic　rough　surface　and　the　rigid　flat　plane　(E/R　model),　and　that　of　the　elasto-plastic　rough　surface　and　the　rigid　flat　plane　(P/R　model)　were　simulated.　The　frictional　temperature,　the　contact　pressure　and　the　contact　area　under　two　different　deformation　characteristic　of　the　rough　solid　during　the　sliding　process　were　analyzed.　The　numerical　results　from　the　analysis　and　simulation　showed　that　the　maximum　contact　temperature　of　the　rough　surface　rose　slowly　during　the　constant　sliding.　The　maximum　contact　pressure　and　the　contact　area　fluctuated　within　a　certain　range.　The　contact　pressure　and　the　frictional　temperature　of　the　elastic　contact　(E/R　model)　were　larger　than　those　of　the　elasto-plastic　contact　(P/R　model),　but　the　contact　area　was　much　smaller.　The　results　demonstrated　that　the　elasto-plastic　deformation　of　the　rough　body　had　significant　influence　on　the　result　during　the　thermo-mechanical　analysis　of　the　rough　solid　in　the　friction.