Mechanical　joint　interfaces　widely　exist　in　all　kinds　of　components.　Their　properties　are　extremely　complex　as　there　are　a　variety　of　factors　affecting　contact　characteristics　such　as　material,　surface　roughness,　processing　method　and　heat　treatment.　This　study　investigated　the　static　mechanical　performances　of　joint　interface　under　cyclic　compression　loads.　A　new　joint　model　was　established　and　described　as　one　continuum　with　three　layers　of　materials,　wherein　the　joint　interface　was　assumed　as　a　layer　of　material　with　thickness　h(c).　Then　the　corresponding　theoretical　expressions　of　Total　Equivalent　Elastic　Modulus　(E-t)　and　Interface　Equivalent　Elastic　Modulus　(E-i)　were　proposed.　A　series　of　cyclic　compression　experiments　were　conducted.　And　the　effects　of　loading　stress,　number　of　cycles　and　surface　roughness　on　Et　and　Et　was　discussed　respectively.　Results　indicated　that　Et　increases　first　and　then　levels　off　with　the　stress　increasing.　Et　approaches　a　steady　state　with　the　increasing　number　of　cycles.　And　the　modulus　decreases　with　the　increase　of　surface　roughness　of　the　joint　interface.　In　addition,　Et　is　a　function　of　Et　and　the　thickness　of　joint　interface　hc.　The　cumulative　plastic　strain　occurs　with　a　repeated　loading　on　the　joint　interface.