The curve number (CN) method improved by US Soil Conservation Service was used to estimate the flood potential of a forested watershed. In this method, the degree of vegetation cover is used along with general descriptions such as good and weak. These two levels of classification (good and weak) can decrease the sensitivity of the calculations and can also generate a large difference between the resulting CN values. Moreover, in the original SCSCN method there is no litter layer term, which is an important hydrological parameter for forested watersheds. Thus, it has been necessary to revise the original method in order to use it more effectively in forested watersheds by taking into account the additional parameters of canopy cover and litter layer thickness.