Abstract: Alcoholic liquors containing carbamide are treated with the urease which has the optimal pH for the activity in an acid region, especially in the region of pH2 to 5. By such treatment, the carbamide can be completely decomposed and removed from the alcoholic liquors in a much smaller amount of urease and in a short time as compared with a conventional treatment according to a urease having the optimal pH in the neutral to alkaline region. This method is more advantageous from the viewpoint of practical use and the quality of the thus obtained alcoholic liquors are superior to that obtained by the conventional treatment.