Cellulosic substance which plays an important role in carbon cycle is most abundant in the nature world. Some higher fungi are able to digest cellulose directly to satisfy their carbohydrate requirement. Then, in order to investigate the enzymatic components of Lenzites betulina (Fr.) being wood rot, that fungus was collected in Kwangneung area. The carpophore of the fungus was smashed with cool distilled water, extracted and salted out by ammonium sulfate. And then the precipitate was purified by dialysing with visking tube and dissolved with pH 7.8 ammonia water, and the extract was filtrated. The fraction of filtrate was obtained as light brown powder after lyophilization, and determined cellulolytic activity. Cellulolytic potency of Lenzites betulina (Fr.) was 1. 65 unit/ml. The cellulase of Lenzites betulina (Fr.) was stable at below $45^{circ}C$ and range of pH $4.5{sim}6.0$ and is completely inactivated at $60^{circ}C$ for 15 minutes. The optimum condition for the enzymatic reaction was $40^{circ}C$ and pH 4.0. The enzyme activity was not influenced by the presence of $Ca^{2+}$ and $Fe^{2+}$.