The hemicelluloses of the fossil tree (Metasequoia glyptostroboides) were isolated from a mildly-prepared acid chlorite holocellulose. Arabinoxylan, glucomannan, and galactoglucomannan were isolated from the holocellulose by extraction and fractionation techniques. The sugar compositions of the polysaccharides were analyzed by quantitative thin layer chromatography and gas chromatography. The hemicelluloses accounted for 21–22% of the wood; the arabinoxylan about 10%, the glucomannan about 6.3%, and the galactoglucomannan about 4.8%. The glucose:mannose ratio for the glucomannan and galactoglucomannan were approximately 1:1.6 and 1:1.7, respectively, in contrast to a ratio of 1:3 commonly found in coniferous woods.