This study investigated the properties of low-flow parameters in storage function equation, of which represented by relation of exponential, using the hourly hydrological model for four mountainous basins. The Au - N exponential equation includes two parameters of α and β. The hydrological analysis was performed for selected six N values in the range of 1 to 105 with the range of Au value determined by trial and error. The result shows that parameter β equaled to 1, therefore the Au - N relationships were represented by inversely proportional equation. In addition, storage function equation can be expressed by only one parameter of α, which is the specific value for each basin.
