The tsunami of 2011 Tohoku Pacific-Coast Earthquake broke river-ice, and generated ice jam in Hokkaido, Japan. This study aimed to clarify the phenomenon of ice jam generated by tsunami in ice covered river. We built the river-ice calculation model. In order to check the accuracy of this calculation model, we conducted ice jam experiment and a calculation value reproduced an experiment value. We understood that it was important to set up "the conditions to generate of ice jam" and "the allowable stress of river-ice" appropriately in this calculation model. This following phenomenon was found by Simulation of Ice Jam. At the time of tsunami intrusion to ice-covered river, River-ice was destroyed and moved to the upstream. River-ice was deposited in narrow river-width. Ice jam was generated at this point.
