The　multiaxial　fatigue　behavior　on　notched　specimen　of　GH4169　super　alloy　has　been　studied.　Full　reversed　axial,　torsional　strain　controlled　fatigue　testes　were　conducted　at　650°C,　by　using　a　MTS　809　tension-torsional　servo-controlled　electro-hydraulic　testing　machine　with　proportional　and　non-proportional　loading.　The　phase　between　axial　strain　and　torsional　strain　were　0°　in-phase　(proportional)　and　45°,　90°　out-of-phase　(non-proportional)　respectively.　A　new　multiaxial　fatigue　damage　criterion　based　on　the　critical　approach　has　been　proposed.　The　results　of　life　prediction　show　that　the　new　fatigue　life　prediction　model　are　validated　with　experimental　results.