Abstract: Barley bran and wheat bran were fermented by Lactobacillus plantarum. Effect of fermentation time and the addition of fermented bran on the pH and TTA values as well as the rheofermentation properties and the quality of breads were studied. The results indicated that pH and TTA values of dough were increasing with the addition of 10% to 30% unfermented bran. Besides, pH values were descending and TTA values kept rising during the fermentation. The proper fermentation time (8 or 16h) and supplementation (20%) of bran sourdough improved the rheological and fermentation properties. Hm, Tx and R values increased to maximum which was closed to the control by adding 20% barley bran sourdough fermented for 8h or 20% wheat bran sourdough fermented for 16h. However, the excessive fermentation (24h) and additive amount (30%) lowered Hm, Tx and R values. When unfermented bran sourdough were added, specific volume of bread reduced and hardness increased. The structure of crumb became loose and the air hole enlarged. While the baking qualities and sensory scores of breads were more acceptable with 20% barley or wheat bran sourdough after 8h or 16h fermentation.