Abstarct: Abstract Assessing the potential damage of flood events is one of the necessary measures in flood management. Due to the lack of sufficient hydrometric stations in Iran's watersheds on the one hand and the lack of sufficient hydrological data in most of the stations on the other, watershed modeling, including flood simulation and the resulting damage, plays an important role in water resources management. This research deals with the estimation of structural flood damage using the depth-damage function (DDF) in AqQala, Iran. For this purpose, the flood depth data, the extent of flood damage, and the coordinates of each point were first obtained using field data and questionnaires filled out by local people in AqQala. Then, the depth-damage function was determined through data analysis. The flood depth was estimated at every point in the region by simulating the flood using HEC-RAS software. Finally, the flood damage map for the area was specified by combining the results of the flood simulation and the damage function in ArcGIS. The results demonstrated that, to estimate the depth-damage function, among the types of linear, power, and logarithmic functions, polynomial is the best logarithmic function with a correlation coefficient of 0.94. Determining the damage map for the return periods of 2, 10, 25, 50, 100, 500, and 1000 shows that the structural damage averages for thats are 10/12, 11/22, 12/05, 15/43, 17/57, 22/69, and 30/21, respectively.