Abstract: The constituents of the Matricaria recutita L. essential oil from Yongdeng of Gansu were analyzed by GC/MS and MassWorks^TM software. The suitable chromatography and mass spectrometry conditions for the analysis of chamomile essential oil were determined by comparing the separation results in two different polarity columns. 35 kinds of compounds were identified. MassWorks can determine the accurate molecular weight of compounds and provide important basis for the low-resolution quadrupole mass spectrometer to identifying the elemental compositions and the structure of compound, as well as provide a new technical means for the component analysis of the essential oils.