The　main　objective　of　this　study　is　to　analyze　the　influence　of　joint　interface　on　mechanical　behavior　of　two　cylinders　by　modeling　different　geometry　with　Finite　Element　Method　(FEM).　The　structures　are　continuum　model　(CM),　joint　interface　model　with　different　materials　(JIM1)　and　joint　interface　model　with　same　materials　(JIM2).　The　displacement-load　relationship,　equivalent　plastic　strain　(EPS),　deformation　and　contact　pressure　based　on　three　models　are　gained.　FEM　results　indicate　that　under　the　same　load,　the　displacements　of　three　models　are　various　in　loading　and　unloading　processes.　The　EPSCM　is　relative　stable　originally　and　then　decerase　quickly　while　the　EPSJIM1　and　EPSJIM2　grow　rapidly　and　fall　slowly　later.　The　deformation　of　CM,　JIM1　and　JIM2　under　300Mpa　are　62.5　mu　m,　33　mu　m　and　68.13　mu　m　respectively.　The　contact　pressure　of　JIM1　is　smaller　than　JIM2.　The　effects　of　frictional　coefficients　(vary　from　0　to　1.0)　on　deformation　and　contact　pressure　are　also　investigated.　Results　show　that　joint　interface　make　the　structure＇s　behaviors　different　compared　with　continuum　structure　and　this　study　can　provide　reference　for　the　design　of　structures　with　joint　interface　in　machinery.