Some regularities of abies-wood oxidative delignification by acetic acid-hydrogen peroxide mixture under the action of suspended TiO2 catalyst and UV pretreatment of wood pulp were studied. The combined action of TiO2 catalyst and of UV-pretreatment of abies-wood allow to produce at optimal conditions of the delignification process the chemically pure cellulose containing no residual lignin. The major characteristics of cellulose product obtained from abies-wood correspond to the characteristics of microcrystalline cellulose.