There is a significant possibility to increase load bearing capacities of thin walled three-dimensional nailing plates by optimization. Nevertheless design of three-dimen sional nailing plates has an inadequate support in Standards. It is the subject of the Author’s research to improve this state by developing optimization method based on 3D FEM calculation method assisted by testing. This paper is focused on the process of optimization. The paper describes the progress of the experiments, their evaluation and analysis of the results in Abaqus FEM software.