The chemical components in traditional Chinese medicine (TCM) are responsible for their therapeutic effects and very important in the modernization of TCM.The components in comus officinalis were analyzed and identified by using electrospray ionization IT-TOF tandem mass spectrometry (LCMS-IT-TOF) in this paper.Five standards(Gallic acid, Morronisid, Sweroside, Loganin, Cornuside) were firstly analyzed using LC/MS method.The MSn spectrurn and fragment pathway of these standards were gained and studied.Then the sample was analyzed.Main components from extracts of comus officinalis were detected and identified using liquid chromatography-ion trap/time-of-flight hybrid mass spectrometry.Extracts was analyzed by LC/MS method with MS1 mode and automatic MS3 mode, 36 components from extracts was identified.The identification process and fragmentation pathway of two compounds (7-O-galloyl-D-sedoheptulose and loganic acid) of these components were shown based on fragmentation pathway of standards and automatic MS3 data.