In order to brew Takju, Korean flour wine, it requires three necessary steps for specific brewage. One is primary brewing process and another main brewing process to sacharify and perform alcoholic fermentation. After previous two brewing passing, the mash of main brewing process mixed with 1 volume of water is commercial Takju. Three samples were obtained from three breweries and incubated at $28{pm}1^{circ}C$for the alcoholic fermentation. All the samples were analyzed for observation of the changes of various biochemical constituents which were contained in the mashes of two brewing processes and in Takju. The starch contents of the suspensions in the primary and main mashes, and in Takju were 28.08, 25.92, 3.83%, and decreased considerably within 36-48 hrs and thereafter slowly. The amounts of water soluble carbohydrates and reducing sugars in three steps had a tendency of decreasing within 48 hours. The initial numbers of yeasts per 1ml in the suspensions were $1.74{ imes}10^8$, $1.65{ imes}10^8$, $0.66{ imes}10^8$, appeared the highest at 72 hours (12.66%) in main process, and in the case of Takju kept increasing untill 60 hours. The dextrin contents in the mashe of primary process through the long period were 0.34 - 0.68%, in the main one were 0.12 - 0.32%, concerning with the amylase activities which were stronger in the mash of the primary process than in that of the main. The contents of methanol and cellulose in the mashes of two processes were 3.40-0.68%, in the main one were 0.12-0.32%, concerning with the amylase activities which were stronger in the mash of the primary process than in that of the main. The contents of methanol and cellulose in the mashes of two processes were 3.40-5.98mg/ml, 0.43-0.48% during the fermentation. The consumption of crude protein the mashes of Takju revealed with time, on the contrary, the production of free amino acids and oligo-peptides were performed, depending upon the affection of proteinase. The amount of tannic acid in Takju was 0.0073-0.0098mg/ml and organic acids of these three groups increased with time and hydrogen ion concentration was 3.28-4.43.