The　microstructures　of　a　centrifugal　spray　deposition　(CSD)　TiAl　alloy　after　different　low　cycle　fatigue　deformations　were　investigated　by　means　of　transmission　electron　microscopy.　The　results　show　that　the　substructure　of　different　dislocation　configurations,　stacking　faults　and　twins　inside　the　specimens　vary　with　the　cyclic　strain　amplitude.　The　substructure　evolution　evolves　from　long　and　straight　dislocations　to　curved　dislocations　and　loops　patches　with　the　increasing　of　cyclic　strain　amplitude,　and　finally　stacking　faults　and　twins　are　also　found　at　the　higher　cyclic　strain　amplitudes.　Furthermore,　some　typical　kinds　of　interfacial　dislocation　configurations　are　found　during　different　deformation　stages　of　low　cycle　fatigue.