For lactic acid fermentation of chestnut broth,10 strains of bacteria were isolated from human feces and commercial yogurt,6 of which were identified to be Bifidobacterium and the rest isolated from Acidities of the chestnut broths fermented by these strains were lower than yogurt, but more than two times higher than yogurts made from seeds or vegetables including soy milk. To stimulate acidity of the fermented broths, addition of yeast extract and tryptone peptone were the most effective at the concentration of 0.2 and 0.4%, respectively, while glucose addition above 0.5% up to 8% did not increased the acid production except a few strains of Lactoba- Cillus. Among the tested fruits and vegetables, carrot juice supplementation was the most effective in acid produc- tion by most of the tested strains. Saccharification of chestnut broth by hydrolyzing process greatly increased the acid production at 25% of cooked chestnut. However, compared to the results from the 8% of unhydrolyzed chest- nut, the net increase in acid production by hydrolysis was not much stimulative.