A　series　of　uni-axial　tensile　cycling　tests　were　conducted　at　room　temperature　in　superelastic　NiTi　strip　specimens　with　nano-grain　size.　The　NiTi　superelastic　strip　specimen＇s　Apparent　Young＇s　Modulus　(AYM)　and　the　critical　stress　decrease　when　the　specimen　is　subjected　to　an　external　uni-axial　stress　and　the　strain　being　higher　than　1.5%.　Both　of　the　AYM　and　the　critical　stress　become　steady　after　10-time　cycling.　The　number　of　the　(111)[1　(4)　over　bar3]　oriented　grains　increases　with　extending　the　strain　value.　The　sub-grain　size　grows　with　increasing　mechanical　cycling　number　due　to　the　annihilation　of　the　small　angle　boundaries.　The　AYM-softening　is　related　to　the　grain　re-orientation　(texture　evolution)　and　the　formation　of　irreversible-stabilized　B19＇　martensitic　variants.　The　softness　of　the　critical　stress　is　principally　attributed　to　the　aspect　that　the　grains　re-orient　to　align　along　the　two　textural　components　(111)[1　(1)　over　bar0]　and　(111)[1　(4)　over　bar3]　when　the　external　stress　being　applied.　The　rotation　of　grains　towards　the　observed　orientation　gives　higher　Schmid　factor　for　the　transformation　and　is　one　of　the　reasons　for　the　decrease　in　AYM　and　critical　stress.　The　orientation　relationships　between　B2　parent　phase　and　the　strain-induced　B19＇　martensite　are　observed　to　be:　[111](B2)　//　[10　(1)　over　bar](M),　(1　(1)　over　bar0)(B2)　//　(010)(M)　and　[111](B2)　//　[(1)　over　bar　10](M)　and　(1　(1)　over　bar0)(B2)　//　(001)(M).