Abstract: Heibu Yaogao (ointment), which made of Galla chinensis, Scolopendra, etc., is a commonly used hospital preparation with definite clinical efficacy, yet its material basis has not been fully clarified.By ultra-high performance liquid chromatography with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS/MS), the chemical constituents of Heibu Yaogao (ointment) and its crude drug mixture were qualitatively analyzed, and the differences of components before and after preparation were discussed.Scanned by electrospray ionization (ESI) source in positive and negative ion modes, a total of 73 compounds were identified via precise molecular weight, characteristic fragment ions and chromatographic retention time.57 and 65 compounds were detected in crude drug mixture and Heibu Yaogao (ointment) respectively, including tannins, phenolic acids, nucleosides, amino acids, etc.In the process of preparation, the chemical structure changes are mainly concentrated in tannins.The change of components of Heibu Yaogao (ointment) before and after processing were proved by UPLC-Q-TOF-MS/MS, which provides important reference for elucidating the material basis of Heibu Yaogao (ointment), illustrating the rationality of preparation technology and further promoting the quality control of the preparation.