Investigation of flooding potential of watershed basins is has considerable importance for identifying of site selection of watershed projects. For this purpose many different indices are used. Two of the most important and applicable indices are F and f indices which are based on derived peak flow from mathematical models. The objective of this study is selection of appropriate index of flooding potential for identifying of site selection of sensitive area to flood production in Jiroft dam basin. In this regard، we used rainfall-runoff (HEC-HMS) model and RS &GIS techniques. Results showed that the values derived using f index had a high correlation coefficient about 81% with values ofcurve number index، so that by varying of the modified curve number، values of this index also varies linearly. In this way f index was selected as a suitable index for flooding potential of region. Finally prioritize map of effective areas in flood peak was plotted in GIS environment.