Аннотация:A method was developed for the preparation of new hydrated cellulose fibers from flax cellulose solutions in N-methylmorpholine-N-oxide using the method of solid-phase activation of cellulose-solvent system. The solubility of flax cellulose in this solvent was examined, a comparative analysis of the rheological behavior of flax cellulose and wood cellulose solutions was carried out, and the temperature and concentration conditions for the production of hydrated cellulose fibers were optimized. X-ray diffraction and IR–Fourier spectroscopic analyses revealed a more pronounced structural ordering of the fibers formed from flax cellulose compared with those obtained from Baikal wood cellulose. The mechanical characteristics of the new fibers conform to the level of commercial hydrated cellulose samples, so flax cellulose may be considered an alternative source of raw materials for obtaining hydrated cellulose fibers suitable as carbon fiber precursors.