The Radix of Gentiana macrophylla (Gentianaceae) has been used for dispelling wind-damp, relaxing the sinews, and clearing heat from deficiency. In order to evaluate its quality, the method for the quantitative determination of gentiopicroside as standard compound has been developed. Gentiopicroside was a major compound of Gentianae Macrophyllae Radix. It was analyzed by HPLC using 30% MeOH as a solvent system. The amount of gentiopicroside from Gentianae Macrophyllae Radix was in the range of $2.22{pm}1.22%;(n=18)$.