The　finite　element　analysis　of　the　elasto-plasticity　connection　of　the　tubular　joints　under　the　action　of　cycle　tensile　load　has　been　made,　the　mechanical　characteristics　of　the　tubular　joints　shown　under　the　action　of　cycle　load,　particularly　the　cycle　laws　and　the　amplitudes　at　the　collection　position　(the　root　of　the　first　joggle.　tooth)　of　the　stress　and　strain　have　been,given.　The　local　stress　and　strain　analysis　method　was　used　to　predict　the　fatigue　life　of　the　tubular　joints.　The　result　shows　that　the　fatigue　life　of　the　tubular　joints　of　J55　with　1.5,　1.75,　and　2　turns　of　normal　coning　was　more　than　three　years　under　the　cycle　tensile　load　of　60similar　to120kN.