To improve the reliability of numerical simulations, hydraulic experiments and numerical simulations of 3-D and plane 2-D models in the case of the Hamaoka Nuclear Power Station site were carried out. The hydraulic experiments were conducted using a 28 m long and 11 m wide plane test tank. The scale of models was 1/150. As the results of the hydraulic experiments, tsunami flowed into the site in the state of jet flow. When the high velocity flow dashed against the front of a structure, the water level went up higher than the maximum water head. As the results of the numerical simulations, the 3-D and plane 2-D models reproduced the hydraulic experiments reasonably well. However, in case that the high velocity flow dashed against the front of a structure, the 3-D model showed more accurate results of water level wave pattern.