The results of a study of the products of the hydrolysis and oxidative cleavage according to Barry of cotton-plant-stem xylan has shown that its main chain consists of 1→4-β-L-anhydroxylopyranose units. Each elementary link of the xylan contains 6–7 xylopyranose units and has two side chains formed by residues of D-glucose and D-glucuronic acid, which are attached in position 2 or 3 of the xylose units of the main chain.