Tsunami evacuation buildings are considered as effective countermeasures against tsunami. The openings of buildings may reduce the tsunami force acting them, however, its effect may be influenced by inner configuration of buildings. Moreover, a tsunami direction is another important factor for tsunami forces. In this study, based on hydraulic experiments and numerical calculations, their effects on tsunami forces are investigated. The tsunami force after impact is found to be estimated by hydraulic pressure in different ways according to the size of openings, and for the buildings with large openings, it is confirmed to be considered forces acting on inner walls. In investigation of tsunami direction, the force due to obliquely incident tsunami can be determined by the tsunami acting area and effect of parry the tsunami.