The effect of high-energy radiation on wood and cellulose was investigated. By irradiation of beech wood, changes in lignin, in carbohydrates and in wood structure take place. Furthermore, new lignin carbohydrate complexes are formed. A way is shown to prevent undesirable reactions. Irradiated pulp possesses a lower degree of polymerization and a higher accessibility for chemical reactions. Processing irradiated pulp to viscose fibres will be more efficient.