In　this　paper,　the　deformation　behavior　of　a　nickel-based　single-crystal　super-alloy　with　[140]　and　[340]　orientations　was　studied　at　room　temperature　by　in　situ　electron　backscattered　diffraction　(EBSD)　tensile　equipment.　The　mechanical　properties,　slip　behavior　and　the　corresponding　Schmidt　factor　were　analyzed.　The　deformation　bands　generated　during　the　plastic　deformation　stage　were　found　and　characterized　by　using　the　electron　backscattered　diffraction　(EBSD)　technique.　Furthermore,　the　formation　and　propagation　of　deformation　bands　played　a　softening　effect　on　stress-strain　curves;　however,　the　secondary　slip　bands　occurring　after　the　propagation　of　deformation　bands　played　a　hardening　effect.　Finally,　the　formation　of　deformation　band　and　its　propagation　on　the　mechanical　properties　are　discussed.