The　effect　of　deformation　temperature　on　the　mechanical　properties　and　deformation　mechanism　of　Fe-20Mn-3Cu-1.3C　twinning　induced　plasticity　(TWIP)　steel　when　deformed　at　-100-200　was　analysed　by　temperature　controlled　tensile　tests.　The　microstructure　of　tensile　samples　was　observed　and　analysed,　and　then　the　effect　between　stacking　fault　energy　of　TWIP　steels　and　deformation　temperature　was　calculated　by　thermodynamic　model.　The　results　show　that　with　the　deformation　temperature　increasing　from-100　to　200,　the　stacking　fault　energy　of　this　steel　gradually　increases,　but　the　volume　fraction　of　twins　gradually　decreases.　The　tensile　strength　and　yield　strength　will　gradually　decline,　while　the　elongation　of　this　steel　firstly　increases,　then　decreases.　Furthermore,　in　this　process,　the　plastic　strain　mechanism　is　transformed　from　twinning　to　slipping.　The　stacking　fault　energy　γSFE　is　calculated　by　the　equation　γSFE=26.73+9.38×10-2T+4.22×10-4T2-4.47×10-7T3.　As　compared　with　slipping,　the　twinning　can　obtain　higher　strain　hardening　rate,　which　leads　to　high　strength　and　plasticity　of　the　TWIP　steel.　©　2016,　Beijing　Institute　of　Aeronautical　Materials　(BIAM).　All　right　reserved.