This paper describes the effects of jetties constructed symmetrically on both banks of a flume with uniform width, which is related to the model study of the Port of Kochi to protect properties and human lives from casualties due to Tsunamis. In this experiement, basic hydraulic values concerned with local corration and deposition, the distribution of current velocity at the mouth of jetties, water level difference, and the distribution of water level, etc. are obtained and discussed. The experiment was conducted on non-uniform flow without considering the undulation of Tsunamis as long period waves.