In this study, tensile tests of plate-fin structures with a DIC measurement system are conducted to investigate validity of the homogenization analysis method developed by our research group. For this, tensile tests using plate-fin test specimens made of an epoxy are performed, and the tests are measured by a DIC measurement system. Then, corresponding elastic-viscoplastic analysis of plate-fin structures is carried out using the homogenization theory for nonlinear time-dependent materials. The analysis results obtained are compared with the experimental results to validate the present method.