Using the numerical analysis of tsunami run-up and inundation, safety assessment of river levee, damage prediction by tsunami inundation and countermeasures for the safety of residents are considered. For the past examination, fixed bed model were used for the numerical analysis even in the area of river mouth where the sand bar is well developed and the reflection and dissipation of tsunami wave and sand deposit in the channel were prominent. In this study, movable bed model for tsunami wave proposed by Takahashi et al.(1999) was used to analyze the dominant factor for the computational accuracy in order to apply this model to tsunami run up in the river. Kiku-river was chosen for applicability evaluation and tsunami prevention measures were considered through the results obtained from proposed model.