In ports damaged by Tsunami after The 2011 off the Pacific coast of Tohoku Earthquake, secondary damages were occurred by collision of drifting objects such as container. To reduce those secondary damages, it is important to predict the drifting-motion. In this research examining mechanisms of drifting container, at first, physical experiment was conducted using solitary wave. Then, numerical experiment was conducted under the same conditions using "Solid-Gas-Liquid Coupled CADMAS-SURF/3D". At last, the model applicability was evaluated. In conclusion, the results showed that, in the experimental conditions of this study, this model can be applied to the simulation of container drift.