A qualitative analytical method based on quadrupole time-of-flight tandem mass spectrometry (UHPLC-Q-TOF-MS/MS) was developed for identification of multi-constituents of raw Magnolia (RM) and processed Magnolia (GM).UHPLCQ-TOF-MS/MS qualitative analysis was performed under positive and negative ion modes and a total of 35 chemical compounds were identified.The analysis data were subjected to a principle component analysis with a t-test.Five peaks were found to be the main difference (P<0.05) between RM and GM.The results indicated that there was higher magnatriol，magnolol，tetradecanoic acid，palmitic acid，chlorogenic acid in GM than in RM.However，there were fewer levels of globulol in the GM than RM，which may be the main reason for different clinical efficacy of RM and GM.