The present invention provides a method for extracting glucan and mannan from the cell wall of a microorganism. Specifically, the method of the present invention in one embodiment comprises the steps of: a) treating the cells of the microorganism with an alkaline protease and an mannanase; b) separating the mixture from step a) into a heavy phase and a light phase; c) drying the heavy phase obtained from step b), obtaining the glucan preparation; and d) drying the light phase obtained from step b), obtaining the mannan preparation. Optionally, in the step c), the heavy phase obtained from step b) may be treated sequentially with an alkali and an acid, and separated again into a heavy phase and a light phase. The heavy phase is dried, obtaining the glucan preparation. The present invention further relates to the glucan preparation and mannan preparation produced thereby, and the uses thereof.