A galactoglucomannan (alkline soluble) and a galactoglucomannan (water soluble) were isolated from the holocellulose of the wood (metasequoia glyptostroboidcs) which contains 40% cellulose, 31% lignin, 25% hemicellulose. The former has Dpn 112, [a]D-23.4?and, on hydrolysis, yields galactoss, glucose, mannose in themolar ratio of 0.1:1.0:2.4. The latter has DPn 86, [a]D-9.1?and sugar ratio of 0.48:1.0:2.0. Each has a main chain of 1? linked D-mannopyranosyl and D-glucopyranosyl residues, but the latter has more D-galactopyranosyl residues attached to C-6 of D-mannopyranosyl.The structures of the mannans from Metasequoia glyptostroboidcs are similar to mannans found in other softwood, but there are differences in their sugar ratios.