Property characterization of nanomaterials is challenged by the small size of the structure be-cause of the difficulties in manipulation Here we demonstrate a novel approach that allows a direct measurement of the mechanical properties of individual nanotube-like structures by in-situ transmission electron microscopy (TEM). The technique is powerful in a way that it can directly correlate the atomic-scale microstructure of the carbon nanotube with its physical properties, providing a one-to-one correspondence in structure-property characterization Applications of the technique will be demonstrated on mechanical properties, the electron field emission and the ballistic quantum conductance in individual nanotubes. Property characterization of nanomaterials is challenged by the small size of the structure be-cause of the difficulties in manipulation Here we demonstrate a novel approach that allows a direct measurement of the mechanical properties of individual nanotube-like structures by in-situ transmission electron microscopy ( TEM). The technique is powerful in a way that it can directly correlate the atomic-scale microstructure of the carbon nanotube with its physical properties, providing a one-to-one correspondence in structure-property characterization Applications of the technique will be demonstrated on mechanical properties, the electron field emission and the ballistic quantum conductance in individual nanotubes.