Radix Dipsaci (RD), the dried root of Dipsacus asper, is used in traditional Chinese medicine as a remedy for bone fractures, traumatic hematoma, threatened abortion, and uterine bleeding. A novel ultra high-performance liquid chromatography coupled with quadrupole-time-of-flight tanderm mass spectrometry (UHPLC-Q-TOF/MS) approach was performed to rapidly characterize the chemical constituents of RD. Consequently, 21 compounds, including 12 iridoid glycosides (IGs), 4 furofuran lignans (FLs), and 5 phenolic acids (PAs) were discovered and identified from RD. Among these compounds, 3 IGs were previously unreported. Furthermore, a rapid and reliable UHPLC-DAD-based method was developed. The linearity (R2>0.999), repeatability (RSDs<3.0%), intra-day and inter-day precision (RSDs<1.6%), recovery (98.9%–102.5%), limits of detection (0.2–2.75ng), and limits of quantification (0.75–8.5ng) of the method was validated. The method was successfully applied for the simultaneous determination of 11 compounds in 20 batches of RD collected from various geographical regions in China. Different RD samples exhibited significantly varied contents of 11 analytes, among which IGs and PAs are abundant compounds that could be used as suitable quality markers for RD. The present study provided a useful approach for comprehensively evaluating the chemical composition and quality of RD.