Two arabinans were isolated in pure form, from the water-soluble extract of red gram cotyledons. Their structures were determined by a combination of methods including GC-MS and NMR. Both the arabinans were highly branched, with a backbone of a+arabinose units joined by 1+5 linkages and branched through O-2 and/or O-+3 linkage. Terminal sugar residues in arabinan I were exclusively arabinofuranose, while in arabinan II, both furanose and pyranose forms of arabinose were present. These differences may account for the differences in their solubility.