Abstract: As a traditional Chinese medicine, Danggui Shaoyao San(DSS) was mainly used for gynecological disease in ancient times, and nowadays used for senile dementia, gynecological disease, hypoimmunity and so on. In our research for the active fraction of DSS, DSS-A-N30 was found to have an analgesic activity. Two new compounds were isolated from DSS-A-N-30 and identified their chemical structures. To further study the activity and structural modification of the two new compounds, a sensitive and specific method was developed for the attribution of them in DSS-A-N-30 by using high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS). Experiments were performed on a triple-quadrupole tandem mass spectrometer using positive electrospray ionization(ESI), and multiple reaction monitoring(MRM) was applied. The results show that the two new compounds are attributed to Atractylodes macrocephala Koidz..