Abstract:Oxytropis ochrocephala Bunge has been characterized as one of the most destructive plants to livestock in the North-Western China. Its chemical components have not been studied. We have been isolated four flavonoids from the aerial parts of Oxytropis ochrocephala Bunge. They have been identified as quercetin, rhamnocitrin, isoquercitrin and rhamnocitrin-3-glucoside by UV, IR, 1HNMR and MS spectra of these flavonoids. Their acetyl derivatives have been prepared and their 1HNMR and MS spectra are fully in accord with this conclusion. The rhamnocitrin-3-glucoside has been found first of all in Oxytropis species. It is perhaps valuable for chemotaxonomy of Oxytropis genus.