Hypsometric Integral (HI) can quantitatively describe the geomorphic evolution stage of the drainage basin. It is one of the important methods of quantitative geomorphic analysis and has been widely used. However, the commonly used method is the elevation fluctuation ratio method, which can only get the result value and can not draw the visual integral curve. This paper presented a method of extracting and drawing HI curve by using ArcGIS and Excel. Firstly, on the basis of understanding the meaning of HI, the characteristics of watershed digital elevation model data (DEM) were analyzed. The analysis results showed that the attribute table stores the elevation value and the corresponding number of grids, in which the number of grids can be converted into area. According to this feature, the watershed DEM was extracted by ArcGIS and its attribute table was constructed. And then the elevation value and its corresponding watershed area were calculated from the attribute table by Excel, so as to obtained a series of area-altitude pairs. The HI curve was drawn by using this numerical sequence. This paper took Datong River Basin as an example to illustrate and verify the method. The calculated results were consistent with the elevation fluctuation ratio method. This method needs no programming, is simple and easy to operate, and is convenient for the wide use of area elevation integration method.