Flood on the earth, especially in our country is caused too much damages in human beings and properties. The aim of this study is an assessment of damages due to occurrence of flood in Golpayegan River. At first, by selecting suitable statistical distribution, river discharges were determined by different return periods. The river cross sections were specified by HEC-GEORAS software. This software was linked with Arcmap software and then data inserted in HEC-RAS software. By using of these data, vulnerable areas were determined. After that the assessment of damage was done using method of American army engineer group (HEC-FDA software). This software would estimate annual damages based on Mont Carlo simulation Results show that the highest damage is related to municipal Keywords : Flood, HEC-FDA, HEC-RAS, HEC-GEO RAS, Golpayegan
