Various mass spectrometric techniques were used for the structural elucidation of Ñavonoid glycosides isolated from green parts of yellow lupin plants (Lupinus luteus). A methodological approach is proposed consisting of (1) extraction and puriÐcation of Ñavonoid glycosides from plant tissues, (2) registration of liquid secondary ion mass spectra of intact compounds and (3) gas chromatographic/mass spectrometric analyses of those compounds subjected to several types of chemical modiÐcation. On the basis of these data, it was possible to deÐne the molecular mass of the glycosides, the structure of the aglycones, the conÐguration of sugar moieties and the position of glycosidic linkages between sugars in diglycosides or between aglycone and sugar moieties. Analysis of the mass spectrometric data permitted structural identiÐcation of four Ñavonoid diglycosides, where the aglycones had Ñavone, isoÑavone and Ñavonol structures. They were recognized as : apigenin 7-O-(2/-Orhamnopyranosyl)glucopyranoside (1), genistein 4º,7-O-diglucopyranoside (2), kaempferol 3-O-(6/rhamnopyranosyl)glucopyranoside (3) and 3º-or 4º-methylquercetin 3-O-(6/-O-rhamnopyranosyl)glucopyranoside (4). Complete structural evaluation of Ñavonoid glycosides was possible with only submilligram quantities of samples needed to register various mass spectra. It was not possible, however, to deÐne the anomeric conÐguration of the C-1 carbons in investigated glycosides.