Ginseng drugs are reported to have multiple health benefits, which are believed to boost energy, lower blood sugar and cholesterol levels. However, ginseng products can vary in their components and medicinal properties. Panax ginseng, American ginseng and radix pseudostellariae are different medical substances. Therefore, it is of great significance to accurately and quickly identify them for the quality control and clinical medication safety of TCM (traditional Chinese medicine). However, the identification of the botanical origins of crude drugs through anatomical and chemotaxonomical studies is limited. It is noted that the effective identification of the herbal species can be interpreted by terahertz wave. The frequency range of the terahertz wave is from 100 GHz to 3 THz. Most of the vibrational and rotational energy levels of biological macromolecules are in the terahertz band. Terahertz time-domain spectroscopy (THz-TDS) is used to obtain the time-domain spectrum of ginseng drugs at room temperature. It was shown that we can discriminate different ginseng samples by the terahertz waves.