To investigate the characteristics of volatile organic compounds from thunbergii, latifoliu and aurantiacu, the independently developed proton transfer reaction mass spectrometer was applied to detect the compounds. Mass spectra of the compounds from thunbergii, latifoliu and aurantiacu at three different voltages of drift tube (250 V, 320 V and 461 V) were obtained. The results showed that m/z of the characteristic product ions of thunbergii were 171, 105, 91, 87, 73 and 69, m/z of ions of latifoliu were 120, 105, 91, 77, 73 and 69, and m/z of ions of aurantiacu were 137, 73, 69 and 51. Through comparative analysis, it was found that there were several common characteristic product ions, but the product ions and its intensity from different species of Osmanthus fragrans presented differences. The experimental results show that the instrument can achieve rapid detection and characteristic product ions can be used to identify different species of Osmanthus fragrans. Proton transfer reaction mass spectrometry has been applied in monitoring volatile organic compounds in environmental and the experimental results have certain reference to environmental gas monitoring.