Nine flavonol oligosides of quercetin and kaempferol with glucose, xylose, and rhamnose as sugars were isolated from the seeds of Aesculus hippocastanum L. (Hippocastanaceae). Five of them are new compounds (2 trisaccharides, 1 bisdesmoside, a nicotinic and a indolinone hydroxyacetic acid ester of the bisdesmoside). Their structures were elucidated mainly using (1)H- and (13)C-NMR techniques.