In this study,high resolution mass spectrometry(HRMS) was used to study and characterize carboranes under direct analysis in real time(DART) ionization condition.Generally,good MS signals could be obtained in the determination of carboranes in negative ion DART conditions,which might possibly be the reason of boron cage with “electron deficient” property.In the isotope peaks formed by carboranes containing 10 B atoms at high resolution DART mass spectra,the mass peak with the highest relative abundance normally contains 2 10B atoms and 8 11B atoms.Considering both the accurate high resolution m/z data and isotope mass peaks profile analysis is an effective strategy for qualitative analysis and characterization of carboranes.