Recently, the downsizing of the structure advances in every field. Effects of the anisotropy of crystal grains on the deformation behavior of the micro-nano structures cannot be neglected because the number of the crystal grains included in the structure decrease. Therefore the purpose of this study is to observe the deformation behavior of crystal grains in the polycrystal by speckle interferometry. To achieve this purpose, specimens, a measuring equipment of the displacement and the tensile testing equipment are produced. Pure aluminum included about 8 crystal grains of several millimeters by processing heat-treatment is used as specimens to observe the deformation behavior of crystal grains. The tensile testing equipment which can control accurate displacement and hold small specimens and both the tension and the compression are possible is designed. Electronic speckle pattern interferometry is used for the measuring strains. The displacement behavior of crystal grains is observed under the tension and the compression. Then, the displacement distribution and the strain components are analyzed each crystal grain. Effects of the anisotropy of crystal grains on the deformation behavior of the micro-nano structures are clarified.