The fast atom bombardment (FAB) mass spectra and mass-selected ion kinetic energy spectra [MIKES] of sodium adduct ions [M + Na]+ of six phenylpropanoid glycosides have been studied. An intense sodium adduct appeared in their FAB mass spectra, which was more abundant than the corresponding protonated molecular ion [M + H]+ and may give more definite information about molecular weight of the sample. The MIKES of these [M + Na]+ ions provided a convenient way for sugar sequence analysis of such glycosides.