A modernized scheme of the structure of native cotton cellulose microfibrils is proposed, providing for the presence of slit-shaped pores in its structure and satisfying most of the results of modern studies of its supramolecular structure and sorption properties. It is shown that within the framework of this scheme it is possible to determine the content of elementary fibrils in microfibrils and the degree of crystallinity of cellulose using 1H-NMR and sorption measurements. The mechanism and character of dispersion of microfibrils, accompanied by supramolecular rearrangements of moistened cellulose, was investigated.