In recent years, flood disasters have occurred frequently due to heavy rainfall, and the importance of evacuation of residents has been increasing and basin-wide flood control is being promoted. Hence, hazard information needs to be improved. However, small and medium-sized rivers lack hazard information. Therefore, the purpose of this study is to propose a flood inundation analysis method suitable for small and medium-sized rivers with insufficient data by using topographic elevation data. The river flow discharge was calculated using the assumed maximum rainfall in Hokuriku region. River cross sections are generated for each granularity of topographic elevation data by 5-meter mesh topographic elevation data, 1-meter mesh aerial laser survey data. Calculation of levee breach locations using 1-meter mesh aerial laser survey data. Flood inundation calculations were performed using 5m mesh topographic elevation data for flood plain. From the results of the analysis, use of river cross-section data prepared by the most detailed data in the existing is recommended. In addition, there is a possibility that potential levee breach locations could be investigated by aerial laser survey data and field survey data.