(1)The main acidic components apart from the sulfites in the cooking iqu ors are determined at the several steps during the digestion with Karamatsu. (2)For the reasons that when no seasoning as the sawdust of the heart wood, the black digestion occurs more vigorously than a long time seasoning (12months) the author stated that when no seasoning, the black digestion starts from galactose-2 bisulfite compound.