A novel method has been developed for simultaneous qualitative analysis of coumarins in the rhizome of Angelica polymorpha Maxim. with the use of high-performance liquid chromatography (LC)-photodiode array detection (DAD)-electrospray ionization (ESI)-tandem mass spectrometry (MS). LC analysis was performed on an Agilent Eclipse XDB-C 18 analytical column with a gradient solvent system of water and methanol, ultraviolet (UV) absorption detection was at 300 nm and peak UV spectrum and (?) ESI-MS data were acquired by DAD and a quadrupole mass spectrometer, respectively. Eight peaks were identified as linear furocoumarins including aviprin, isopimpinellin, bergapten, isooxypeucedanin, gosferol, imperatorin, phellopterin and isoimperatorin by comparing their retention time, UV, and MS spectra with that of the authentic standards, and the analysis of UV spectra and ESI-MS data of the standards gave the characteristics of UV absorption and ESI-MS fragmentation. On the basis of the above characteristics, the possible structures of four other linear furocoumarins were deduced in LC. The other chemical structures were proposed as three angular furocoumarins, a simple coumarin, two chromones, and a cinnamic acid by comparing their UV and MS data with that of literature reports. Accordingly, the method we established can simply and accurately identify the key chemical constituents in the rhizome of A. polymorpha.