One-dimensional (1D) nanostructures have numerous potential applications in science and engineering. Nanocomposites made of nanowires, such as carbon nanotubes, are likely to decrease material's density and increase its strength, [1] which are of critical importance to space technology. To investigate the uniqueness offered by these materials, new techniques must be developed to quantitatively measure the properties of individual wire-like structures'whose structures are well characterized by electron microscopy techniques, because their properties may sensitively depend on their geometrical shape/configurations and crystal as well as surface structures. Within the framework of in-situ TEM we have recently developed a novel approach that relies on electric field induced mechanical resonance for measuring the properties of individual wire-like structures, such as Young's modulus, electron field emission, tip work function, and electrical quantum conductance. This is a new technique that provides the properties of a single nanowire with well characterized.