The main objective of this study is to assess the risk of river flooding from the Jamuna River by using a two-dimensional flood simulation model. Firstly, we examined the methods of the nested flood simulation model focusing on the situation where dry beds are frequently present. Secondly, methods were applied to the target area in Bangladesh. Consequently, the results of the nested method using water depth were superior on the viewpoint of flooded area, depth and volume. Also, the simulation result showed good agreement in terms of the extent of flooding. For the further research, consideration of the roughness depending on the grid size was suggested.