Five main flavonoid glycosides were isolated, for the first time, from the ethanol extract of Desmostachia bipinnata (L.)Stapf ( Gramineae ). They were identified as kaempferol(1), quercetin(2), quercetin-3-glucoside(3), trycin(4) and trycin-7-glucoside(5). The structure elucidation was based on UV, Electrospray ionization mass spectrometry (ESIMS), 1H and 13C NMR, proton- proton correlation spectroscopy ( 1H- 1H Cosy), distortionless enhancement by polarization transfer (DEPT), heteronuclear single quantum coherence (HSQC), and heteronuclear multiple bond correlations spectrum (HMBC). The total extract (200 and 300 mg/kg) and two of the isolated compounds (trycin and trycin-7-glucoside.100 mg/kg each) showed a very promising antiulcerogenic activity with curative ratios; 68.31, 70.54, 77.39 and 78.93%, respectively.