Effect of barrier concerning tsunami flow over hill was simulated by using 2D numerical system CADMAS-SURF/2D. Numerical area included sea shallower than 10m depth, 10m high hill on land, 12m high tsunami barrier, and hinterland. Input condition was 6.5m height wave with half of period 600s. It was found that the tsunami barrier reduced duration of high velocity more than 5m/s to about 10s around the top of hill. However, without the barrier, the high velocity continued for more than 40s there. The maximum tsunami force on the barrier occurred at tsunami flow overflowing. The profile of pressure distribution is similar to a right triangle like hydrostatic pressure.
