Materials in nanometer scale such as nano-film, nano-wire and nano-dot, have unique characteristic behavior, which is conspicuously different from the counterpart of bulk. Our group investigates the mechanical behavior, strength and fracture mechanism of the nanometer scale materials by loading experiments with in situ SEM/TEM observations and by molecular dynamics simulations. We also inquire multi-physics behavior (stress, ferroelectricity and magnetism) of nano-materials focusing on the shape (external geometry: ex. film, wire and dot) and the understructure (inner geometry: ex. Vacancy, dislocation and grain boundary)