in this study, the mechanical properties and deformation mechanism of a niti alloy are investigated using in situ TEM compression, nanoindentation, and vickers hardness tests. the Young's modulus of a niti micropillar measured during an in situ TEM compression experiment was significantly smaller than that obtained by nanoindentation. the mechanical strength of the material is influenced by the annealing temperature. additionally, the size effect of the niti alloy pillared structures on compression and bending was affected by contamination with gallium ions. the mechanical properties, contact behavior, and local bending fracture results for niti alloy nanopillars and blocks are consistent with previous literature reports. these results provide potentially useful information concerning the mechanical properties, contact behavior, and local bending fractures of niti alloy nanopillars and blocks.