Physiological properties of root and stolen of Gamcho (Licorice, Glycyrrhiza uralensis Fischer) were compared following irradiation at 20 kGy. The root and stolen of Gamcho were extracted with 70 % ethanol, irradiated and stoved in a 4"C refrigerator. Irradiation induced color changes, electron donating ability (EDA), and tyro-sinase inhibition effect (TIE) were investigated. The color of the non-irradiated stolen extract was darker than the non-irradiated root extract (p<0.05), but irradiation eliminated color differences between stolen and root extracts. Generally, irradiation did not affect EDA and TIE of either of the extracts. However, EDA and TIE were higher in stolen extract than in root extract, when the higher dilution factor was considered. These results indicate that the stolen of Gamcho, which is mostly wasted, is a valuable source of phytochemicals with greater EDA and TIE activities than Gamcho root.root.