When the oil storage tanks drift from their initial place by tsunami, they may cause severe troubles such as destruction of structures nearby and leaks of storaged oil. Model experiments revealed that the tsunami wave force and friction forces determine the slipping and drifting of the tanks, therefore we constructed a simulation model using the momentum equation for the prediction of the tank movement. The simulation results well represented the track of drifting measured by the model experiment. When the oil tanks start to drift, they tend to drift for several hundred meters unless they remain in the initial place by the force of static friction.