Urticae Rhizoma is a commonly used traditional Chinese medicine.However,its quality evaluation research has not been reported yet.This research is the first study on the quality marker of Urticae Rhizoma.Firstly,the biological activity of urticoside,the main and characteristic component of Urticae Rhizoma,was investigated.The result indicated that urticoside had the significant anti-inflammatory,anti-complement,and antioxidant activities.Subsequently,a systematic study of the spectral characteristics of urticoside,by using UV,HR-MS,NMR,FT-IR,and CD technologies,was carried out.As results,the UV,IR,and CD spectral data of urticoside were supplemented;the determination solvents had the significant effects on NMR and UV spectra.Finally,the contents of urticoside in Urticae Rhizoma were determined by HPLC method.The determination results revealed that the contents of urticoside in different species of Urticae Rhizoma were very different,and urticoside could be used as the quality marker of Urticae Rhizoma.